After removing the same mod from both the client and server, I am unable to join my server due to leftover block ids, with the error "Failed to synchronize registry data from server, closing connection" shown on my screen. This is not LAN. Is this a forge bug? I'm using Minecraft v1.16.5 and Forge v36.1.24.
In this case, Ore Stone Variants is the mod with removed blocks, this happens with any mod that is removed.
Server Debug Log
Server Log
Client Log (Line 5559)