Our best guess is that the game hasn't been optimized in any way. No matter what the system is, it struggles once you have a lot of items (all those full chests we got boiiiii) in a small area. Our seagulls don't fly half the time near our base, just stop in mid air, and our buildings aren't even that serious. It'll be smooth sailing at 60 fps in the ocean, then we turn the bend into our camp and BOOM, it's like playing on a comodor.