The bumper seems like it is getting pined by some debris inside or, could be a bad momentary push button (clicker). The only way to see is to open the controller. Tutorial found here: https://www.youtube.com/watch?v=vc9c5qeE1hQ
It's not difficult if you have the right tools:
-plastic spudger.
-torx screwdriver set.
-soldering iron (motor removals)
If it is a bad momentary push button, you'll need to solder a new button on which can be difficult and will need quite a bit of skill and patience.