Something I have noticed is when you are possessing a mob that can hold items, the damage it can do is set to the strongest weapon they have held. For instance if I am possessing a zombie and I hold a diamond sword my damage attribute will go to 9, and it will stay at 9 even if I stop holding the sword. Then, if I switch to a netherite sword, it will go to 10 and once again stay at 10 even if I switch back to a diamond sword or switch off the netherite sword completely. I don't seem to be able to fix it using commands, as when I try to change the modifier or base damage of the entity or player it just reverts back. Also this only seems to happen on multiplayer, on singleplayer it works fine.

Hmm, can't reproduce it myself on multiplayer, is it linked to specific mods ?

Possibly, the other mods the server I'm running has are lithium, voicechat, runelic, krypton, and a discord integration mod. my guess if it were to be a mod doing it it would probably be lithium or krypton since the other 3 dont mess with anything related to it but I don't know for sure

Probably related to #567, thanks for the additional details 👍