https://github.com/Unity-Technologies/com.unity.netcode.gameobjects/issues/2920

It's hard to be precise with this issue as I'm unsure exactly what's causing it.
But in one of my scenes, I get the following error:
!https://private-user-images.githubusercontent.com/22588585/329207721-25bb0a2f-aa59-4162-a874-7e4a64bd7fe5.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.wqAI0Sm-4wiGVnNF3joQWTL3Q-Ezy0Rg2a-KB7QPzuc!

It continuously spams the log while the game is playing.
I've attempted to track down which object it is related to, and I've managed to delete an object, and even a script, which then stops the issue, but then it seems to come back again after a restart related to a different object. I couldn't track down any code that could've caused this - and with the stacktrace being entirely inside of Netcode, it's hard to figure it out.

The weird part is, as far as I remember, I had netcode 1.9.1 working in this exact scene with no errors for a while. I keep a full git history, so I went back to a point where it was working previously, and it is no longer working.
I've deleted the Library, obj and other folders and still no luck.

There are cases where I've been trying to narrow down the object thats creating this bug - and I play the game with that object deleted, and still get the bug. But then I play the game again, and then the bug isn't there - and I haven't changed anything since the last play.
If I leave said object deleted, restart Unity, then the first play will have this error, subsequent ones will not...

This scene works completely fine in NGO 1.7.1 & 1.8.1
h3. Environment

Windows 11
NGO 1.9.1
Unity 2023.2.9f1