When you go off the end of the map on your map, the character on the map goes to the middle of the map and depending on your X coordinates, the character on the map will go left or right and stay in the center of the map.

(I think it only happens on the top of the map because when I tried the bottom it didn’t happen)

(Another edit: I found out that when you go on the left side of the map, you go to the center but it’s the opposite with the top of the map. Instead of the player still going left or right with the X coordinate, now you go up or down with the Y coordinate.)