With SwitchPresence enabled, I can't seem to boot modded Smash with the sysmodule active. Splatoon 3 works fine, leading me to believe that it's either something with the game itself or Arcropolis. Either way, wouldn't hurt to update SwitchPresence for 16.0.0 since it hasn't been touched in a while.
Edit: the error likely has to do with firmware updates altering the way that socket services function. This hasn't been updated in a few years.