Same hereI’m having the same issues. Playing on switch 2, the game works completely fine on single player but lags and crashes on split-screen.

After more hours of gameplay, the lag spikes and crashes have become so frequent, that I would almost consider split screen unplayable on the switch.I have been experiencing this problem as well. Completely new Switch 2, while playing split screen coop. There are a lot of random lag spikes, I have only had 1 crash so far (been playing for a few hours). My crash happened right after saving, so no progress was lost.
Spilt screen is way too heavy for such a new console. The game didn't get the chance to get especially optimised for the Switch 2.After more hours of gameplay, the lag spikes and crashes have become so frequent, that I would almost consider split screen unplayable on the switch.