update

Based on peer review, folding the same logic for spawn authority resetting dirty once spawned to assure no duplicate changes are sent.

Author: NoelStephensUnity

com.unity.netcode.gameobjects/Runtime/Core/NetworkBehaviour.cs

@@ -838,7 +838,7 @@ internal void NetworkPostSpawn()
             // all spawn related methods have been invoked.
             for (int i = 0; i < NetworkVariableFields.Count; i++)
             {
-                NetworkVariableFields[i].OnSpawned();
+                NetworkVariableFields[i].InternalOnSpawned();
             }
         }
 
@@ -891,7 +891,7 @@ internal void InternalOnNetworkPreDespawn()
             // all spawn related methods have been invoked.
             for (int i = 0; i < NetworkVariableFields.Count; i++)
             {
-                NetworkVariableFields[i].OnPreDespawn();
+                NetworkVariableFields[i].InternalOnPreDespawn();
             }
         }
 

com.unity.netcode.gameobjects/Runtime/NetworkVariable/Collections/NetworkList.cs

@@ -58,28 +58,6 @@ public NetworkList(IEnumerable<T> values = default,
             Dispose();
         }
 
-        internal override void OnSpawned()
-        {
-            // If the NetworkList is:
-            // - On the spawn authority side.
-            // - Dirty
-            // - State updates can be sent:
-            // -- The instance has write permissions.
-            // -- The last sent time plus the max send time period is less than the current time.
-            // - User script has modified the list during spawn.
-            // When the NetworkObject is finished spawning (on the same frame), go ahead and reset
-            // the dirty related properties and last sent time to prevent duplicate entries from
-            // being sent (i.e. CreateObjectMessage will contain the changes so we don't need to
-            // send a proceeding NetworkVariableDeltaMessage).
-            if (m_NetworkObject.IsSpawnAuthority && IsDirty() && CanWrite() && CanSend())
-            {
-                UpdateLastSentTime();
-                ResetDirty();
-                SetDirty(false);
-            }
-            base.OnSpawned();
-        }
-
         /// <inheritdoc cref="NetworkVariable{T}.ResetDirty"/>
         public override void ResetDirty()
         {

com.unity.netcode.gameobjects/Runtime/NetworkVariable/NetworkVariable.cs

@@ -407,30 +407,5 @@ internal override void WriteFieldSynchronization(FastBufferWriter writer)
                 base.WriteFieldSynchronization(writer);
             }
         }
-
-        /// <summary>
-        /// Notification we have fully spawned the associated <see cref="NetworkObject"/>.
-        /// </summary>
-        internal override void OnSpawned()
-        {
-            // If the NetworkVariable is:
-            // - On the spawn authority side.
-            // - Dirty.
-            // - State updates can be sent:
-            // -- The instance has write permissions.
-            // -- The last sent time plus the max send time period is less than the current time.
-            // - User script has modified the list during spawn.
-            // When the NetworkObject is finished spawning (on the same frame), go ahead and reset
-            // the dirty related properties and last sent time to prevent duplicate updates from
-            // being sent (i.e. CreateObjectMessage will contain the changes so we don't need to
-            // send a proceeding NetworkVariableDeltaMessage).
-            if (m_NetworkObject.IsSpawnAuthority && IsDirty() && CanWrite() && CanSend())
-            {
-                UpdateLastSentTime();
-                ResetDirty();
-                SetDirty(false);
-            }
-            base.OnSpawned();
-        }
     }
 }

com.unity.netcode.gameobjects/Runtime/NetworkVariable/NetworkVariableBase.cs

@@ -140,27 +140,37 @@ public void Initialize(NetworkBehaviour networkBehaviour)
             }
         }
 
-        /// TODO-API: After further vetting and alignment on these, we might make them part of the public API.
-        /// Could actually be like an interface that gets automatically registered for these kinds of notifications
-        /// without having to be a NetworkBehaviour.
-        #region OnSpawn and OnPreDespawn (ETC)
-
         /// <summary>
         /// Invoked after the associated <see cref="NetworkBehaviour.OnNetworkPostSpawn"/> has been invoked.
         /// </summary>
-        internal virtual void OnSpawned()
+        internal void InternalOnSpawned()
         {
-
+            // If the NetworkVariableBase derived class is:
+            // - On the spawn authority side.
+            // - Dirty.
+            // - State updates can be sent:
+            // -- The instance has write permissions.
+            // -- The last sent time plus the max send time period is less than the current time.
+            // - User script has modified the list during spawn.
+            // When the NetworkObject is finished spawning (on the same frame), go ahead and reset
+            // the dirty related properties and last sent time to prevent duplicate updates from
+            // being sent (i.e. CreateObjectMessage will contain the changes so we don't need to
+            // send a proceeding NetworkVariableDeltaMessage).
+            if (m_NetworkObject.IsSpawnAuthority && IsDirty() && CanWrite() && CanSend())
+            {
+                UpdateLastSentTime();
+                ResetDirty();
+                SetDirty(false);
+            }
         }
 
         /// <summary>
         /// Invoked after the associated <see cref="NetworkBehaviour.OnNetworkPreDespawn"/> has been invoked.
         /// </summary>
-        internal virtual void OnPreDespawn()
+        internal void InternalOnPreDespawn()
         {
 
         }
-        #endregion
 
         /// <summary>
         /// Deinitialize is invoked when a NetworkObject is despawned.