I don't play bullet, but I recently got a new Android phone and I just reinstalled the Android app after a long period using the website only. It worked very well.
I had no problems with having to re-enter moves repeatedly. I suppose it is possible that chess.com and lichess define what constitutes a move tap within a square differently. Is it any tap anywhere in a defined x by x pixel area? I would think, however, that a tap to select a button (or square) would work the same across all apps.
I don't know what you were searching for help with. I doubt there is any help available on adjusting button sensitivity.
However, if you wanted to make a suggestion, you can do that by using the AI to make a suggestion on the Support site.
https://support.chess.com/en/articles/8583752-how-do-i-report-a-bug-or-make-a-suggestion
I've recently reinstalled chess.com on my new Galaxy tablet (after not being on here for a while) and it still sucks. It is incredibly clunky, nothing like Lichess in terms of smoothness and speed (when playing Bullet).
I've played around with all the settings, including the Settings that are in the actual game and it is still utterly unplayable. Multiple times during a Bullet game I've needed to press the same square just to get the move to work, it seems as though the area of the square that activates a move is very small and seems to be literally just in the very centre of it.
By the way, the AI help is an even worse experience. Nearly as bad as all the pop ups....