I have recently set up my own custom controls for my tablet the way I like it. Anyway I went into scaffolding and the controls went haywire basically and broke. I have attached a video demonstration of the glitch.
I think it only works on d-pad.
Happens in both survival and creative

Here:
https://1drv.ms/v/s!AuGXzZh_yMrOhUe0hUChisziQncb?e=GPSh9v