diff --git a/apps/testing/src/pages/PlaygroundPage.tsx b/apps/testing/src/pages/PlaygroundPage.tsx
index 3ea64d6fa..13b7c1e31 100644
--- a/apps/testing/src/pages/PlaygroundPage.tsx
+++ b/apps/testing/src/pages/PlaygroundPage.tsx
@@ -4,5 +4,11 @@ import { defaultProps } from '../libs/const.ts';
 
 export function PlaygroundPage() {
   const props = useConfigParams(defaultProps);
-  return <GroupChannelApp {...props} breakpoint={/iPhone|iPad|iPod|Android/i.test(navigator.userAgent)} config={{ logLevel: 'all' }} />;
+  return <GroupChannelApp {...props} breakpoint={/iPhone|iPad|iPod|Android/i.test(navigator.userAgent)} config={{ logLevel: 'all' }} 
+    uikitOptions={{
+      groupChannel: {
+        replyType: 'thread',
+      }
+    }}
+  />;
 }
diff --git a/package.json b/package.json
index 27ef0095d..bc83d6853 100644
--- a/package.json
+++ b/package.json
@@ -70,9 +70,9 @@
     "react-dom": "^16.8.6 || ^17.0.0 || ^18.0.0 || ^19.0.0"
   },
   "dependencies": {
-    "@sendbird/chat": "^4.18.0",
-    "@sendbird/react-uikit-message-template-view": "^0.0.10",
-    "@sendbird/uikit-tools": "^0.0.10",
+    "@sendbird/chat": "^4.20.0",
+    "@sendbird/react-uikit-message-template-view": "^0.0.18",
+    "@sendbird/uikit-tools": "^0.0.18",
     "css-vars-ponyfill": "^2.3.2",
     "date-fns": "^2.16.1",
     "dompurify": "^3.2.4"
diff --git a/src/modules/Channel/context/hooks/useHandleChannelEvents.ts b/src/modules/Channel/context/hooks/useHandleChannelEvents.ts
index 99df31eca..e316a8571 100644
--- a/src/modules/Channel/context/hooks/useHandleChannelEvents.ts
+++ b/src/modules/Channel/context/hooks/useHandleChannelEvents.ts
@@ -121,7 +121,6 @@ function useHandleChannelEvents({
         },
         onUserMarkedUnread: (channel, userIds) => {
           logger.info('Channel | useHandleChannelEvents: onUserMarkedUnread', channel, userIds);
-          // TODO:: MADOKA 이 부분에 대해서 명확하게 확인해야 함.
           if (compareIds(channel?.url, channelUrl)) {
             messagesDispatcher({
               type: messageActions.MARK_AS_UNREAD,
@@ -169,11 +168,13 @@ function useHandleChannelEvents({
           });
         },
         onReactionUpdated: (channel, reactionEvent) => {
-          logger.info('Channel | useHandleChannelEvents: onReactionUpdated', { channel, reactionEvent });
-          messagesDispatcher({
-            type: messageActions.ON_REACTION_UPDATED,
-            payload: reactionEvent,
-          });
+          if (channel.isGroupChannel() && compareIds(channel?.url, channelUrl)) {
+            logger.info('Channel | useHandleChannelEvents: onReactionUpdated', { channel, reactionEvent });
+            messagesDispatcher({
+              type: messageActions.ON_REACTION_UPDATED,
+              payload: reactionEvent,
+            });
+          }
         },
         onChannelChanged: (channel) => {
           if (channel.isGroupChannel() && compareIds(channel?.url, channelUrl)) {
diff --git a/src/modules/GroupChannel/components/MessageList/index.tsx b/src/modules/GroupChannel/components/MessageList/index.tsx
index a55a13f60..519ceaf7e 100644
--- a/src/modules/GroupChannel/components/MessageList/index.tsx
+++ b/src/modules/GroupChannel/components/MessageList/index.tsx
@@ -110,7 +110,7 @@ export const MessageList = (props: GroupChannelMessageListProps) => {
 
   // Find the first unread message
   const firstUnreadMessage = useMemo(() => {
-    if (!enableMarkAsUnread || !isInitializedRef.current || messages.length === 0 || readState === 'read') {
+    if (!enableMarkAsUnread || !isInitializedRef.current || messages.length === 0 || readState === 'read' || !currentChannel?.myLastRead) {
       return undefined;
     }
 
diff --git a/src/modules/Thread/components/ThreadList/ThreadListItemContent.tsx b/src/modules/Thread/components/ThreadList/ThreadListItemContent.tsx
index 89e6ce61e..947e053b9 100644
--- a/src/modules/Thread/components/ThreadList/ThreadListItemContent.tsx
+++ b/src/modules/Thread/components/ThreadList/ThreadListItemContent.tsx
@@ -332,6 +332,7 @@ export default function ThreadListItemContent(props: ThreadListItemContentProps)
           toggleReaction,
           isOpenedFromThread: true,
           deleteMessage,
+          resendMessage,
           onDownloadClick: async (e) => {
             if (!onBeforeDownloadFileMessage) return;
 
diff --git a/src/modules/Thread/context/hooks/useThreadFetchers.ts b/src/modules/Thread/context/hooks/useThreadFetchers.ts
index f34da3a2b..3f1dfce8d 100644
--- a/src/modules/Thread/context/hooks/useThreadFetchers.ts
+++ b/src/modules/Thread/context/hooks/useThreadFetchers.ts
@@ -30,6 +30,7 @@ function getThreadMessageListParams(params?: Partial<ThreadedMessageListParams>)
     prevResultSize: PREV_THREADS_FETCH_SIZE,
     nextResultSize: NEXT_THREADS_FETCH_SIZE,
     includeMetaArray: true,
+    isInclusive: true,
     ...params,
   };
 }
diff --git a/src/modules/Thread/context/useThread.ts b/src/modules/Thread/context/useThread.ts
index 2ec79319c..be328924f 100644
--- a/src/modules/Thread/context/useThread.ts
+++ b/src/modules/Thread/context/useThread.ts
@@ -10,6 +10,7 @@ import {
   BaseMessage,
   MultipleFilesMessage,
   ReactionEvent,
+  SendingStatus,
   UserMessage,
 } from '@sendbird/chat/message';
 import { NEXT_THREADS_FETCH_SIZE, PREV_THREADS_FETCH_SIZE } from '../consts';
@@ -26,6 +27,8 @@ import useUpdateMessageCallback from './hooks/useUpdateMessageCallback';
 import useDeleteMessageCallback from './hooks/useDeleteMessageCallback';
 import { useThreadFetchers } from './hooks/useThreadFetchers';
 
+import { cloneDeep } from 'lodash';
+
 function hasReqId<T extends object>(
   message: T,
 ): message is T & { reqId: string } {
@@ -56,6 +59,10 @@ const useThread = () => {
 
   const sendMessageStatusActions = {
     sendMessageStart: useCallback((message: SendableMessageType) => store.setState(state => {
+      if ('sendingStatus' in message) {
+        (message as SendableMessageType).sendingStatus = SendingStatus.PENDING;
+      }
+
       return {
         ...state,
         localThreadMessages: [
@@ -66,6 +73,10 @@ const useThread = () => {
     }), [store]),
 
     sendMessageSuccess: useCallback((message: SendableMessageType) => store.setState(state => {
+      if ('sendingStatus' in message) {
+        (message as SendableMessageType).sendingStatus = SendingStatus.SUCCEEDED;
+      }
+
       return {
         ...state,
         allThreadMessages: [
@@ -81,6 +92,10 @@ const useThread = () => {
     }), [store]),
 
     sendMessageFailure: useCallback((message: SendableMessageType) => store.setState(state => {
+      if ('sendingStatus' in message) {
+        (message as SendableMessageType).sendingStatus = SendingStatus.FAILED;
+      }
+
       return {
         ...state,
         localThreadMessages: state.localThreadMessages.map((m) => (
@@ -92,6 +107,10 @@ const useThread = () => {
     }), [store]),
 
     resendMessageStart: useCallback((message: SendableMessageType) => store.setState(state => {
+      if ('sendingStatus' in message) {
+        (message as SendableMessageType).sendingStatus = SendingStatus.PENDING;
+      }
+
       return {
         ...state,
         localThreadMessages: state.localThreadMessages.map((m) => (
@@ -235,16 +254,16 @@ const useThread = () => {
 
     initializeThreadListSuccess: useCallback((parentMessage: BaseMessage, anchorMessage: SendableMessageType, threadedMessages: BaseMessage[]) => store.setState(state => {
       const anchorMessageCreatedAt = (!anchorMessage?.messageId) ? parentMessage?.createdAt : anchorMessage?.createdAt;
-      const anchorIndex = threadedMessages.findIndex((message) => message?.createdAt > anchorMessageCreatedAt);
+      const anchorIndex = threadedMessages.findIndex((message) => message?.createdAt === anchorMessageCreatedAt);
       const prevThreadMessages = anchorIndex > -1 ? threadedMessages.slice(0, anchorIndex) : threadedMessages;
-      const anchorThreadMessage = anchorMessage?.messageId ? [anchorMessage] : [];
       const nextThreadMessages = anchorIndex > -1 ? threadedMessages.slice(anchorIndex) : [];
+
       return {
         ...state,
         threadListState: ThreadListStateTypes.INITIALIZED,
         hasMorePrev: anchorIndex === -1 || anchorIndex === PREV_THREADS_FETCH_SIZE,
         hasMoreNext: threadedMessages.length - anchorIndex === NEXT_THREADS_FETCH_SIZE,
-        allThreadMessages: [prevThreadMessages, anchorThreadMessage, nextThreadMessages].flat() as CoreMessageType[],
+        allThreadMessages: [...prevThreadMessages, ...nextThreadMessages] as CoreMessageType[],
       };
     }), [store]),
 
@@ -397,18 +416,25 @@ const useThread = () => {
     }), [store]),
 
     onReactionUpdated: useCallback((reactionEvent: ReactionEvent) => store.setState(state => {
-      if (state?.parentMessage?.messageId === reactionEvent?.messageId) {
-        state.parentMessage?.applyReactionEvent?.(reactionEvent);
+      let updatedParentMessage = state.parentMessage;
+      if (state.parentMessage?.messageId === reactionEvent?.messageId) {
+        updatedParentMessage = cloneDeep(state.parentMessage as SendableMessageType);
+        updatedParentMessage.applyReactionEvent(reactionEvent);
       }
+
+      const updatedMessages = state.allThreadMessages.map((m) => {
+        if (reactionEvent?.messageId === m?.messageId) {
+          const updatedMessage = cloneDeep(m as CoreMessageType);
+          updatedMessage.applyReactionEvent(reactionEvent);
+          return updatedMessage;
+        }
+        return m;
+      });
+
       return {
         ...state,
-        allThreadMessages: state.allThreadMessages.map((m) => {
-          if (reactionEvent?.messageId === m?.messageId) {
-            m?.applyReactionEvent?.(reactionEvent);
-            return m;
-          }
-          return m;
-        }),
+        parentMessage: updatedParentMessage,
+        allThreadMessages: [...updatedMessages], // Create new array reference to trigger re-render
       };
     }), [store]),
 
diff --git a/src/ui/Checkbox/index.scss b/src/ui/Checkbox/index.scss
index f7f0df0b3..42e9d731e 100644
--- a/src/ui/Checkbox/index.scss
+++ b/src/ui/Checkbox/index.scss
@@ -79,4 +79,4 @@
     transform: rotate(45deg);
   }
 }
-/**rtl:end:ignore**/
+/*rtl:end:ignore*/
diff --git a/src/utils/storeManager.ts b/src/utils/storeManager.ts
index 2f4f1cf56..dcfb3e0f5 100644
--- a/src/utils/storeManager.ts
+++ b/src/utils/storeManager.ts
@@ -18,6 +18,7 @@ export function hasStateChanged<T>(prevState: T, updates: Partial<T>): boolean {
        */
       return false;
     }
+
     return !isEqual(prevState[key as keyof T], value);
   });
 }
diff --git a/yarn.lock b/yarn.lock
index 5c05c4268..1133c5f17 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2747,9 +2747,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@sendbird/chat@npm:^4.18.0":
-  version: 4.19.5
-  resolution: "@sendbird/chat@npm:4.19.5"
+"@sendbird/chat@npm:^4.20.0":
+  version: 4.20.0
+  resolution: "@sendbird/chat@npm:4.20.0"
   peerDependencies:
     "@react-native-async-storage/async-storage": ^1.17.6
     react-native-mmkv: ">=2.0.0"
@@ -2758,29 +2758,28 @@ __metadata:
       optional: true
     react-native-mmkv:
       optional: true
-  checksum: b67d3b9413ae1b61c4261ef540f7b31b21fec925950a2805ac2cb0eac2c981ec001f8d066bce8fc294d6a104a4ad2a0481c1e907e59fa9bcc8a0081411b729c6
+  checksum: ad614ef86f382aab8c41b333e02f6eab87409650c44d3aad9fab8f67ff3b2ffb331b38c84b3d70cc95cc9cd5f47b0ee568fc50257fa6b3aecd118ac304d7c494
   languageName: node
   linkType: hard
 
-"@sendbird/react-uikit-message-template-view@npm:^0.0.10":
-  version: 0.0.10
-  resolution: "@sendbird/react-uikit-message-template-view@npm:0.0.10"
+"@sendbird/react-uikit-message-template-view@npm:^0.0.18":
+  version: 0.0.18
+  resolution: "@sendbird/react-uikit-message-template-view@npm:0.0.18"
   dependencies:
-    "@sendbird/uikit-message-template": ^0.0.10
+    "@sendbird/uikit-message-template": ^0.0.18
   peerDependencies:
-    "@sendbird/chat": ">=4.3.0 <5"
     react: ">=16.8.6"
     react-dom: ">=16.8.6"
-  checksum: aac92fb0b963c4ee3f31eea05839cd49c5ad8561c427b5778731fdf61bcbc18076b329ab2866f12b776e77e9b2a9bfbba12263bcf25d4949a34ab80120548d2f
+  checksum: 1ce96ee2ff96934aa2d3ce092b2b8799701c5b782e84c04d45fe4dc4cfd3755499de013520edf0f599ce356c941ae1793e5a461d550ecadd14ed5f689f395531
   languageName: node
   linkType: hard
 
-"@sendbird/uikit-message-template@npm:^0.0.10":
-  version: 0.0.10
-  resolution: "@sendbird/uikit-message-template@npm:0.0.10"
+"@sendbird/uikit-message-template@npm:^0.0.18":
+  version: 0.0.18
+  resolution: "@sendbird/uikit-message-template@npm:0.0.18"
   peerDependencies:
     react: ">=16.8.6"
-  checksum: 18dfce8f7c83d37a94bc3cbca0f561d7ed10c4367bcb2d2bf9c9192fce8fa06cfd87e8f968c6f3ae6d464a5119338ee5167b1a055b777bd906664a225c7e486f
+  checksum: c732c8effe55c3cc1f659a41f372e934891828281b03aefc504930bbccfb1ac7c5f7f989217ffeb2dadca98b872aa8bde7fb2c8c92506ce99aba23cf1b89d969
   languageName: node
   linkType: hard
 
@@ -2803,9 +2802,9 @@ __metadata:
     "@rollup/plugin-node-resolve": ^15.2.3
     "@rollup/plugin-replace": ^5.0.4
     "@rollup/plugin-typescript": ^11.1.5
-    "@sendbird/chat": ^4.18.0
-    "@sendbird/react-uikit-message-template-view": ^0.0.10
-    "@sendbird/uikit-tools": ^0.0.10
+    "@sendbird/chat": ^4.20.0
+    "@sendbird/react-uikit-message-template-view": ^0.0.18
+    "@sendbird/uikit-tools": ^0.0.18
     "@storybook/addon-essentials": ^8.5.0
     "@storybook/manager-api": ^8.5.0
     "@storybook/react-vite": ^8.5.0
@@ -2870,13 +2869,13 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@sendbird/uikit-tools@npm:^0.0.10":
-  version: 0.0.10
-  resolution: "@sendbird/uikit-tools@npm:0.0.10"
+"@sendbird/uikit-tools@npm:^0.0.18":
+  version: 0.0.18
+  resolution: "@sendbird/uikit-tools@npm:0.0.18"
   peerDependencies:
     "@sendbird/chat": ">=4.10.5 <5"
     react: ">=16.8.6"
-  checksum: 1b92fe4a5caced7efff4397fdf87912bc958b45f5eae1f986f78961759b18687901cc28bbc6f797a6fb0e1552e56ef5e04a16da0125883f18b00e99fbee5f44b
+  checksum: 045565a9e0df7bd180e9a88da8d23543dedc7628b892c1f7e052f576dbc3529f4272852d93434b644a58933371a160de467d9534112df9f9622ab07ca3706b55
   languageName: node
   linkType: hard