So I had put my Vita down, sleep mode, and came back half an hour later. For whatever reason, Mao was moving to the upper right on the base map (not in combat) and the stick wouldnt stop him. The D-pad would move him in the direction I pressed but if I let go he'd keep moving back to the upper right. If Id enter a menu, the icon would scroll up until I hit up or down, then the up button would no longer function.
Ive tried turning the vita off, Ive tried removing the game, deleting the data. When I tried out a psp game there were no issues. Not sure how to fix this.