Currently the hotbar system on ui to show / hide is by tapping once the arrow button. May I suggest if instead of tapping change it to press and hold to show/hide. I find it sometimes when using hotbar functions on a smaller device I.e smartphones and hitting on the extreme right position of the hotbar , sometimes I accidentally hit the hide/show arrow key instead . It can become annoying when you need to switch real quick at critical moments in fights . Thanks