fix: scene loading event not synchronizing in scene objects (#3096)

* fix

This fixes the issue with in-scene placed NetworkObjects not being synchronized properly when the session owner generates a scene event type load. The service is not considered an observer and when sending a scene event type load it should send all spawned objects.

* update

adding changelog entry

* update

adding associated PR to changelog entry

* update

covering synchronization too.

Author: NoelStephensUnity

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -18,6 +18,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 ### Fixed
 
+- Fixed issue with service not getting synchronized with in-scene placed `NetworkObject` instances when a session owner starts a `SceneEventType.Load` event. (#3096)
 - Fixed issue with the in-scene network prefab instance update menu tool where it was not properly updating scenes when invoked on the root prefab instance. (#3092)
 - Fixed issue where applying the position and/or rotation to the `NetworkManager.ConnectionApprovalResponse` when connection approval and auto-spawn player prefab were enabled would not apply the position and/or rotation when the player prefab was instantiated. (#3078)
 - Fixed issue where `NetworkObject.SpawnWithObservers` was not being honored when spawning the player prefab. (#3077)

com.unity.netcode.gameobjects/Runtime/SceneManagement/SceneEventData.cs

@@ -320,9 +320,11 @@ private void SortParentedNetworkObjects()
         internal void AddSpawnedNetworkObjects()
         {
             m_NetworkObjectsSync.Clear();
+            // If distributed authority mode and sending to the service, then ignore observers
+            var distributedAuthoritySendingToService = m_NetworkManager.DistributedAuthorityMode && TargetClientId == NetworkManager.ServerClientId;
             foreach (var sobj in m_NetworkManager.SpawnManager.SpawnedObjectsList)
             {
-                if (sobj.Observers.Contains(TargetClientId))
+                if (sobj.Observers.Contains(TargetClientId) || distributedAuthoritySendingToService)
                 {
                     m_NetworkObjectsSync.Add(sobj);
                 }
@@ -666,12 +668,14 @@ internal void SerializeScenePlacedObjects(FastBufferWriter writer)
             // Write our count place holder (must not be packed!)
             writer.WriteValueSafe((ushort)0);
             var distributedAuthority = m_NetworkManager.DistributedAuthorityMode;
+            // If distributed authority mode and sending to the service, then ignore observers
+            var distributedAuthoritySendingToService = distributedAuthority && TargetClientId == NetworkManager.ServerClientId;
 
             foreach (var keyValuePairByGlobalObjectIdHash in m_NetworkManager.SceneManager.ScenePlacedObjects)
             {
                 foreach (var keyValuePairBySceneHandle in keyValuePairByGlobalObjectIdHash.Value)
                 {
-                    if (keyValuePairBySceneHandle.Value.Observers.Contains(TargetClientId))
+                    if (keyValuePairBySceneHandle.Value.Observers.Contains(TargetClientId) || distributedAuthoritySendingToService)
                     {
                         // Serialize the NetworkObject
                         var sceneObject = keyValuePairBySceneHandle.Value.GetMessageSceneObject(TargetClientId, distributedAuthority);