Constant crashing and freezing on the switch

Since buying the port for the switch, I've ran into several issues. At first freezing was a big problem, interrupting me about every 15 minutes for up to 20 seconds at a time, but that has, thankfully, stopped. I thought that was the end of it, but whenever I reach the end of the map, whether that was in the underworld or the sea, the game crashes, and I lose whatever progress I've made.

Does anyone know what is the source of my problems? And if so, is there any way to fix this?