Hello !
When left clicking another player with the totem, we both get disconnected.
The error is "Internal Exception: io.netty.handler.codec.DecoderException: java.lang.RuntimeException: Tried to read NBT tag that was too big; tried to allocate: 2097157bytes where max allowed: 2097152".

I cannot reconnect to the server for now, but the one I hit can. I get the same error as above.

We do have Better Combat (1.8.5+1.20.1) installed.
This is on Forge 47.3.0, Minecraft 1.20.1, Alex's Caves 1.1.4, Java 18.0.2.1

Mod list in screens below :

This also happened on an old server without better combat, but that time the possessed player did not get disconnected. The possessing player got disconnected only if they tried moving the possessed player IIRC.

I can send some debug logs at the dev's request but I don't know how to anonymise them.

Using packet fixer on both the server and client fixes the issue. However clients on the server without packet fixer get disconnected when I try to move a possessed player, and it doesn't depend on dimension / distance (a friend got dc although they were in the nether, and me and the possessed player were in the overworld)