diff --git a/packages/core/src/__mocks__/v1/events/events.22mar.ts b/packages/core/src/__mocks__/v1/events/events.22mar.ts
index 8ab57c50a..f6a1d1519 100644
--- a/packages/core/src/__mocks__/v1/events/events.22mar.ts
+++ b/packages/core/src/__mocks__/v1/events/events.22mar.ts
@@ -1,8 +1,10 @@
-import { ObjectId, WithId } from "mongodb";
-import { Priorities } from "../../../constants/core.constants";
-import { Schema_Event } from "../../../types/event.types";
+import { ObjectId } from "bson";
+import { Priorities } from "@core/constants/core.constants";
+import { Schema_Event, WithMongoId } from "@core/types/event.types";
 
-const allDayEventsThatShouldMatch: Array<WithId<Omit<Schema_Event, "_id">>> =
+const allDayEventsThatShouldMatch: Array<
+  WithMongoId<Omit<Schema_Event, "_id">>
+> =
   // ordered by start date
   [
     {
@@ -43,49 +45,50 @@ const allDayEventsThatShouldMatch: Array<WithId<Omit<Schema_Event, "_id">>> =
     },
   ];
 
-const allDayEventsThatShouldNotMatch: Array<WithId<Omit<Schema_Event, "_id">>> =
-  [
-    {
-      _id: new ObjectId(),
-      user: "user1",
-      title: "Feb 28 - Mar 5",
-      isAllDay: true,
-      isSomeday: false,
-      startDate: "2022-02-28",
-      endDate: "2022-03-05",
-      priority: Priorities.WORK,
-    },
-    {
-      _id: new ObjectId(),
-      user: "user1",
-      title: "Mar 5",
-      isAllDay: true,
-      isSomeday: false,
-      startDate: "2022-03-05",
-      endDate: "2022-03-06",
-      priority: Priorities.WORK,
-    },
-    {
-      _id: new ObjectId(),
-      user: "user1",
-      title: "Mar 13",
-      isAllDay: true,
-      isSomeday: false,
-      startDate: "2022-03-13",
-      endDate: "2022-03-14",
-      priority: Priorities.WORK,
-    },
-    {
-      _id: new ObjectId(),
-      user: "user1",
-      title: "Mar 13 - 16",
-      isAllDay: true,
-      isSomeday: false,
-      startDate: "2022-03-13",
-      endDate: "2022-03-17",
-      priority: Priorities.WORK,
-    },
-  ];
+const allDayEventsThatShouldNotMatch: Array<
+  WithMongoId<Omit<Schema_Event, "_id">>
+> = [
+  {
+    _id: new ObjectId(),
+    user: "user1",
+    title: "Feb 28 - Mar 5",
+    isAllDay: true,
+    isSomeday: false,
+    startDate: "2022-02-28",
+    endDate: "2022-03-05",
+    priority: Priorities.WORK,
+  },
+  {
+    _id: new ObjectId(),
+    user: "user1",
+    title: "Mar 5",
+    isAllDay: true,
+    isSomeday: false,
+    startDate: "2022-03-05",
+    endDate: "2022-03-06",
+    priority: Priorities.WORK,
+  },
+  {
+    _id: new ObjectId(),
+    user: "user1",
+    title: "Mar 13",
+    isAllDay: true,
+    isSomeday: false,
+    startDate: "2022-03-13",
+    endDate: "2022-03-14",
+    priority: Priorities.WORK,
+  },
+  {
+    _id: new ObjectId(),
+    user: "user1",
+    title: "Mar 13 - 16",
+    isAllDay: true,
+    isSomeday: false,
+    startDate: "2022-03-13",
+    endDate: "2022-03-17",
+    priority: Priorities.WORK,
+  },
+];
 
 export const mockEventSetMar22: Array<Omit<Schema_Event, "_id">> = [
   ...allDayEventsThatShouldMatch,
diff --git a/packages/core/src/mappers/map.event.ts b/packages/core/src/mappers/map.event.ts
index 2ab298635..31701c947 100644
--- a/packages/core/src/mappers/map.event.ts
+++ b/packages/core/src/mappers/map.event.ts
@@ -1,6 +1,5 @@
 /* eslint-disable @typescript-eslint/no-namespace */
 import mergeWith from "lodash.mergewith";
-import { WithId } from "mongodb";
 import { Origin, Priorities } from "@core/constants/core.constants";
 import { BaseError } from "@core/errors/errors.base";
 import {
@@ -11,6 +10,7 @@ import {
   Schema_Event_Recur_Instance,
   Schema_Event_Regular,
   WithCompassId,
+  WithMongoId,
   WithoutCompassId,
 } from "@core/types/event.types";
 import { WithGcalId, gSchema$Event } from "@core/types/gcal";
@@ -37,9 +37,9 @@ export namespace MapEvent {
   };
 
   export const removeProviderData = (
-    event: WithId<Omit<Schema_Event, "_id">> | Schema_Event,
+    event: WithMongoId<Omit<Schema_Event, "_id">> | Schema_Event,
   ): Omit<
-    WithId<Omit<Schema_Event, "_id">> | Schema_Event,
+    WithMongoId<Omit<Schema_Event, "_id">> | Schema_Event,
     "gEventId" | "gRecurringEventId"
   > => {
     const {
@@ -57,7 +57,7 @@ export namespace MapEvent {
   };
 
   export const removeIdentifyingData = (
-    event: WithId<Omit<Schema_Event, "_id">> | Schema_Event,
+    event: WithMongoId<Omit<Schema_Event, "_id">> | Schema_Event,
   ): Omit<
     Schema_Event,
     | "_id"
@@ -128,7 +128,7 @@ export namespace MapEvent {
 
   export const toGcalSingleProviderData = (
     base:
-      | WithId<Omit<Schema_Event_Recur_Base | Schema_Event_Regular, "_id">>
+      | WithMongoId<Omit<Schema_Event_Recur_Base | Schema_Event_Regular, "_id">>
       | WithCompassId<
           Omit<Schema_Event_Recur_Base | Schema_Event_Regular, "_id">
         >,
@@ -140,11 +140,11 @@ export namespace MapEvent {
 
   export const toProviderData = (
     event:
-      | WithId<Omit<Schema_Event, "_id" | "recurrence">>
+      | WithMongoId<Omit<Schema_Event, "_id" | "recurrence">>
       | WithCompassId<Omit<Schema_Event, "_id" | "recurrence">>,
     provider?: CalendarProvider,
     base?:
-      | WithId<Omit<Schema_Event_Recur_Base, "_id">>
+      | WithMongoId<Omit<Schema_Event_Recur_Base, "_id">>
       | WithCompassId<Omit<Schema_Event_Recur_Base, "_id">>,
   ) => {
     const isCInstance = isInstance(event);
@@ -153,7 +153,7 @@ export namespace MapEvent {
       case CalendarProvider.GOOGLE: {
         return isCInstance
           ? MapEvent.toGcalInstanceProviderData(
-              event as WithId<Omit<Schema_Event_Recur_Instance, "_id">>,
+              event as WithMongoId<Omit<Schema_Event_Recur_Instance, "_id">>,
               base,
             )
           : MapEvent.toGcalSingleProviderData(event);
diff --git a/packages/core/src/types/mongo.types.ts b/packages/core/src/types/mongo.types.ts
index 1f6e9060b..a21f5e548 100644
--- a/packages/core/src/types/mongo.types.ts
+++ b/packages/core/src/types/mongo.types.ts
@@ -1,3 +1,3 @@
-import { ObjectId } from "mongodb";
+import { ObjectId } from "bson";
 
 export type InsertedIds = { [key: number]: ObjectId };
diff --git a/packages/core/src/types/sync.types.ts b/packages/core/src/types/sync.types.ts
index 65bb08228..1761c6c18 100644
--- a/packages/core/src/types/sync.types.ts
+++ b/packages/core/src/types/sync.types.ts
@@ -1,4 +1,4 @@
-import { AnyBulkWriteOperation, BulkWriteResult } from "mongodb";
+import type { AnyBulkWriteOperation, BulkWriteResult } from "mongodb";
 import { BaseError } from "@core/errors/errors.base";
 
 export interface Params_Sync_Gcal extends Payload_Sync_Notif {
diff --git a/packages/core/src/util/event/compass.event.rrule.test.ts b/packages/core/src/util/event/compass.event.rrule.test.ts
index 87144071f..4a2f09996 100644
--- a/packages/core/src/util/event/compass.event.rrule.test.ts
+++ b/packages/core/src/util/event/compass.event.rrule.test.ts
@@ -1,4 +1,4 @@
-import { ObjectId, type WithId } from "mongodb";
+import { ObjectId } from "bson";
 import { RRule } from "rrule";
 import { faker } from "@faker-js/faker";
 import { recurring } from "@core/__mocks__/v1/events/gcal/gcal.recurring";
@@ -7,6 +7,7 @@ import { gEventToCompassEvent } from "@core/mappers/map.event";
 import {
   CalendarProvider,
   type Schema_Event_Recur_Base,
+  WithMongoId,
 } from "@core/types/event.types";
 import dayjs from "@core/util/date/dayjs";
 import { CompassEventRRule } from "@core/util/event/compass.event.rrule";
@@ -390,7 +391,7 @@ describe("CompassEventRRule: ", () => {
         return event;
       });
 
-      const baseEvent = compassEvents.find(isBase) as WithId<
+      const baseEvent = compassEvents.find(isBase) as WithMongoId<
         Omit<Schema_Event_Recur_Base, "_id">
       >;
 
diff --git a/packages/core/src/util/event/compass.event.rrule.ts b/packages/core/src/util/event/compass.event.rrule.ts
index a3af7be33..087a81ef5 100644
--- a/packages/core/src/util/event/compass.event.rrule.ts
+++ b/packages/core/src/util/event/compass.event.rrule.ts
@@ -1,5 +1,4 @@
 import { ObjectId } from "bson";
-import type { WithId } from "mongodb";
 import type { Options, RRuleStrOptions } from "rrule";
 import { RRule, rrulestr } from "rrule";
 import type { ParsedOptions } from "rrule/dist/esm/types";
@@ -9,6 +8,7 @@ import type {
   CalendarProvider,
   Schema_Event_Recur_Base,
   Schema_Event_Recur_Instance,
+  WithMongoId,
 } from "@core/types/event.types";
 import dayjs from "@core/util/date/dayjs";
 import {
@@ -18,13 +18,13 @@ import {
 } from "@core/util/event/event.util";
 
 export class CompassEventRRule extends RRule {
-  #event: WithId<Omit<Schema_Event_Recur_Base, "_id">>;
+  #event: WithMongoId<Omit<Schema_Event_Recur_Base, "_id">>;
   #dateFormat: string;
   #durationMs!: number;
 
   constructor(
     event: Pick<
-      WithId<Omit<Schema_Event_Recur_Base, "_id">>,
+      WithMongoId<Omit<Schema_Event_Recur_Base, "_id">>,
       "startDate" | "endDate" | "_id" | "recurrence"
     >,
     options: Partial<Options> = {},
@@ -41,7 +41,7 @@ export class CompassEventRRule extends RRule {
   }
 
   static #initOptions(
-    event: WithId<Omit<Schema_Event_Recur_Base, "_id">>,
+    event: WithMongoId<Omit<Schema_Event_Recur_Base, "_id">>,
     _options: Partial<Options> = {},
   ): Partial<Options> {
     const startDate = parseCompassEventDate(event.startDate!);
@@ -111,7 +111,7 @@ export class CompassEventRRule extends RRule {
 
   base(
     provider?: CalendarProvider,
-  ): WithId<Omit<Schema_Event_Recur_Base, "_id">> {
+  ): WithMongoId<Omit<Schema_Event_Recur_Base, "_id">> {
     const _id = this.#event._id ?? new ObjectId();
     const recurrence = { rule: this.toRecurrence() };
     const event = { ...this.#event, _id, recurrence };
@@ -129,7 +129,7 @@ export class CompassEventRRule extends RRule {
    */
   instances(
     provider?: CalendarProvider,
-  ): WithId<Omit<Schema_Event_Recur_Instance, "_id">>[] {
+  ): WithMongoId<Omit<Schema_Event_Recur_Instance, "_id">>[] {
     const base = this.base();
     const baseData = MapEvent.removeIdentifyingData(base);
     const baseEventId = base._id.toString();
diff --git a/packages/core/src/util/test/ccal.event.factory.ts b/packages/core/src/util/test/ccal.event.factory.ts
index df8a0d6b4..90d175935 100644
--- a/packages/core/src/util/test/ccal.event.factory.ts
+++ b/packages/core/src/util/test/ccal.event.factory.ts
@@ -1,4 +1,4 @@
-import { ObjectId } from "mongodb";
+import { ObjectId } from "bson";
 import { faker } from "@faker-js/faker";
 import { Origin, Priorities } from "@core/constants/core.constants";
 import {
@@ -8,7 +8,7 @@ import {
   WithCompassId,
 } from "@core/types/event.types";
 import dayjs from "@core/util/date/dayjs";
-import { isAllDay, parseCompassEventDate } from "../event/event.util";
+import { isAllDay, parseCompassEventDate } from "@core/util/event/event.util";
 
 export const createMockStandaloneEvent = (
   overrides: Partial<Schema_Event> = {},
diff --git a/packages/web/src/common/types/web.event.types.ts b/packages/web/src/common/types/web.event.types.ts
index 56a28f853..5c0c79ef7 100644
--- a/packages/web/src/common/types/web.event.types.ts
+++ b/packages/web/src/common/types/web.event.types.ts
@@ -24,7 +24,7 @@ const WebEventRecurrence = z.union([
 ]);
 
 const WebCoreEventSchema = CompassCoreEventSchema.extend({
-  _id: z.union([idSchema, optimisticIdSchema]),
+  _id: z.union([idSchema, optimisticIdSchema]).optional(),
   recurrence: WebEventRecurrence,
   order: z.number().optional(),
 });
diff --git a/packages/web/src/common/utils/event.util.test.ts b/packages/web/src/common/utils/event.util.test.ts
index 02d23596c..4d9ede881 100644
--- a/packages/web/src/common/utils/event.util.test.ts
+++ b/packages/web/src/common/utils/event.util.test.ts
@@ -1,4 +1,10 @@
-import { isEventInRange } from "./event.util";
+import { createMockStandaloneEvent } from "@core/util/test/ccal.event.factory";
+import {
+  Schema_GridEvent,
+  Schema_WebEvent,
+} from "@web/common/types/web.event.types";
+import { isEventInRange } from "@web/common/utils/event.util";
+import { _assembleGridEvent } from "@web/ducks/events/sagas/saga.util";
 
 describe("isEventInRange", () => {
   it("returns true if event is in range", () => {
@@ -9,6 +15,7 @@ describe("isEventInRange", () => {
     };
     expect(isEventInRange(event, dates)).toBe(true);
   });
+
   it("returns false if event is not in range", () => {
     const event = { start: "2022-03-15", end: "2022-03-15" };
     const dates = {
@@ -18,3 +25,31 @@ describe("isEventInRange", () => {
     expect(isEventInRange(event, dates)).toBe(false);
   });
 });
+
+describe("_assembleGridEvent", () => {
+  it("should successfully convert Someday event to Grid event by adding position field", () => {
+    // Create a mock Someday event (without position field)
+    const somedayEvent = createMockStandaloneEvent({
+      isSomeday: true,
+    }) as Schema_WebEvent;
+
+    const generator = _assembleGridEvent(somedayEvent);
+
+    // First, it calls getEventById
+    const getEventStep = generator.next();
+    expect(getEventStep.done).toBe(false);
+
+    // Mock returning the Someday event
+    const validateStep = generator.next({ ...somedayEvent, isSomeday: false });
+
+    // This should now succeed because the fix adds the required position field
+    expect(validateStep.done).toBe(true);
+    const result = validateStep.value as Schema_GridEvent;
+
+    // Verify that position field is now present
+    expect(result.position).toBeDefined();
+    expect(result.position.isOverlapping).toBe(false);
+    expect(result.position.widthMultiplier).toBe(1);
+    expect(result.position.horizontalOrder).toBe(1);
+  });
+});
diff --git a/packages/web/src/common/utils/event.util.ts b/packages/web/src/common/utils/event.util.ts
index a078c7477..4097ccb65 100644
--- a/packages/web/src/common/utils/event.util.ts
+++ b/packages/web/src/common/utils/event.util.ts
@@ -21,10 +21,10 @@ import {
   Schema_OptimisticEvent,
   Schema_WebEvent,
 } from "@web/common/types/web.event.types";
+import { validateGridEvent } from "@web/common/validators/grid.event.validator";
 import { validateSomedayEvent } from "@web/common/validators/someday.event.validator";
-import { validateGridEvent } from "../validators/grid.event.validator";
 
-const gridEventDefaultPosition = {
+export const gridEventDefaultPosition = {
   isOverlapping: false,
   widthMultiplier: 1,
   horizontalOrder: 1,
@@ -87,7 +87,7 @@ export const assembleDefaultEvent = async (
   }
 };
 
-export const assembleGridEvent = (event: Schema_Event): Schema_GridEvent => {
+export const assembleGridEvent = (event: Schema_WebEvent): Schema_GridEvent => {
   const gridEvent: Schema_GridEvent = {
     ...event,
     position: gridEventDefaultPosition,
@@ -97,7 +97,7 @@ export const assembleGridEvent = (event: Schema_Event): Schema_GridEvent => {
     origin: event.origin ?? Origin.COMPASS,
     priority: event.priority ?? Priorities.UNASSIGNED,
     user: event.user!,
-    recurrence: event.recurrence as Schema_Event_Recur_Base["recurrence"],
+    recurrence: event.recurrence,
   };
 
   return gridEvent;
@@ -203,13 +203,10 @@ export const prepEvtAfterDraftDrop = (
   return event;
 };
 
-export const prepEvtBeforeSubmit = (
-  draft: Schema_Event | Schema_GridEvent,
-  userId: string,
-) => {
-  const _event: Omit<Schema_Event | Schema_GridEvent, "recurrence"> = {
+export const prepEvtBeforeSubmit = (draft: Schema_WebEvent, userId: string) => {
+  const _event = {
     ...draft,
-    origin: Origin.COMPASS,
+    origin: draft.origin ?? Origin.COMPASS,
     user: userId,
   };
 
diff --git a/packages/web/src/common/validators/grid.event.validator.ts b/packages/web/src/common/validators/grid.event.validator.ts
index 1cf6e9497..6a54b620a 100644
--- a/packages/web/src/common/validators/grid.event.validator.ts
+++ b/packages/web/src/common/validators/grid.event.validator.ts
@@ -1,7 +1,10 @@
-import { Schema_Event } from "@core/types/event.types";
-import { GridEventSchema, Schema_GridEvent } from "../types/web.event.types";
+import {
+  GridEventSchema,
+  Schema_GridEvent,
+  Schema_WebEvent,
+} from "@web/common/types/web.event.types";
 
-export const validateGridEvent = (event: Schema_Event): Schema_GridEvent => {
+export const validateGridEvent = (event: Schema_WebEvent): Schema_GridEvent => {
   const result = GridEventSchema.parse(event) as Schema_GridEvent;
 
   return result;
diff --git a/packages/web/src/ducks/events/sagas/saga.util.ts b/packages/web/src/ducks/events/sagas/saga.util.ts
index cd59b99e2..550feae04 100644
--- a/packages/web/src/ducks/events/sagas/saga.util.ts
+++ b/packages/web/src/ducks/events/sagas/saga.util.ts
@@ -1,14 +1,20 @@
 import dayjs from "dayjs";
 import { normalize, schema } from "normalizr";
-import { call, put, select } from "redux-saga/effects";
+import { SelectEffect, call, put, select } from "redux-saga/effects";
 import { ID_OPTIMISTIC_PREFIX } from "@core/constants/core.constants";
 import {
   Params_Events,
   RecurringEventUpdateScope,
   Schema_Event,
 } from "@core/types/event.types";
-import { Schema_GridEvent } from "@web/common/types/web.event.types";
-import { replaceIdWithOptimisticId } from "@web/common/utils/event.util";
+import {
+  Schema_GridEvent,
+  Schema_WebEvent,
+} from "@web/common/types/web.event.types";
+import {
+  assembleGridEvent,
+  replaceIdWithOptimisticId,
+} from "@web/common/utils/event.util";
 import { validateGridEvent } from "@web/common/validators/grid.event.validator";
 import { EventApi } from "@web/ducks/events/event.api";
 import { Payload_ConvertEvent } from "@web/ducks/events/event.types";
@@ -22,8 +28,8 @@ export function* getEventById(
   _id: string,
 ): Generator<
   ReturnType<typeof select>,
-  Schema_GridEvent | undefined,
-  Schema_GridEvent | undefined
+  Schema_GridEvent | Schema_WebEvent,
+  Schema_GridEvent | Schema_WebEvent
 > {
   const currEvent = yield select((state: RootState) =>
     selectEventById(state, _id),
@@ -36,7 +42,7 @@ export function* _editEvent(
   gridEvent: Schema_GridEvent,
   params: { applyTo?: RecurringEventUpdateScope } = {},
 ) {
-  yield call(EventApi.edit, gridEvent._id as string, gridEvent, params);
+  yield call(EventApi.edit, gridEvent._id, gridEvent, params);
 }
 
 export function* insertOptimisticEvent(
@@ -58,11 +64,22 @@ export function* insertOptimisticEvent(
 export function* _assembleGridEvent({
   _id,
   ...updatedFields
-}: Payload_ConvertEvent["event"]) {
+}: Payload_ConvertEvent["event"]): Generator<
+  SelectEffect,
+  Schema_GridEvent,
+  Schema_WebEvent
+> {
   const currEvent = yield* getEventById(_id);
 
-  const _gridEvent = { ...currEvent, ...updatedFields };
-  const gridEvent = validateGridEvent(_gridEvent);
+  // First merge the current event with updated fields
+  const eventWithUpdates = { ...currEvent, ...updatedFields, _id };
+
+  // Use assembleGridEvent to ensure position field is properly set
+  const gridEventWithDefaults = assembleGridEvent(eventWithUpdates);
+
+  // Validate the result
+  const gridEvent = validateGridEvent(gridEventWithDefaults);
+
   return gridEvent;
 }