[Andy608]

Follow-up to #1069 (closed for lack of a repro). Still present on 4.7.4 / main; reproduced on 4.7.2 with Unity 6000.3, a macOS dedicated server build and a standalone client build.

What happens

On a dedicated server, a scene stays loaded on the server and connections are moved between scenes with LoadConnectionScenes / UnloadConnectionScenes (by name, AutomaticallyUnload = false). Going A → B works. Going back B → A, the client never loads A:

OnLoadStart  asServer=False Scene_Plaza
OnLoadEnd    asServer=False loaded=(none) skipped=MovedObjectsHolder
SceneId of 4017455039 not found in SceneObjects. ...

The server then spawns A's scene objects to a client that doesn't have A. Every time for us; a host, or a server in the Editor, doesn't show it (the handle numbers don't line up).

Why

1. A is already loaded on the server, so SceneManager (server side, CanLoadScene false) broadcasts new SceneLookupData(s): the client receives the server's handle for A.
2. On the client, CanLoadScene → SceneLookupData.GetScene looks that handle up first, among the client's scenes.
3. Scene handles are process-local. The client's MovedObjectsHolder (made when it unloaded A) had the same number as the server's A, so the client treated A as already loaded and skipped it.

The same lookup resolves unloads, so a collision could also unload the wrong client scene.

Fix

GetScene trusts a handle only in the process that runs the server; a pure client resolves by name.

• The client still echoes the server's lookup data back unchanged (ClientScenesLoadedBroadcast), so the server's handle-based pending-load check still matches.
• Servers and hosts keep handle lookups (their handles are their own).
• Uses InstanceFinder.IsServerStarted, so it assumes one NetworkManager per process.

We've run this patch on 4.7.2: the A → B → A round trip against a dedicated server build went from failing every time to passing every time.

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