I noticed this while playing both TBOI and Castle Crashers. I know its not joystick issue as steam says the controller is inputting %100 all round in the custom deadzone settings. I've tried recalibrating the controller on windows joystick settings which still did not fix the problem. This can be somewhat remedied by setting a custom square deadzone stick, but that causes it to snap more to diagonals. I've seen this problem pointed out by some others before but couldn't find a full fix.