2 players was butter smooth at 75fps but 3+ players is constant slow mo even at framerate set at 60

I can't get this function to work at all, instead I lose the ability to attack at all if I try. What do I have to do to make this work right?

and the delay is very high, but my network is okay, is there a good way to solve it

So I can Remote Play Together the base game which has no co-op option and I can't use it on the Mod can anyone help ?

Died in 1 level revived in the next, lost all my card perks... but the icons of the perks were still on the screen...