Left touch pad not responding to presses

As the title says, my Steam Controller used to work perfectly fine, but now the left touch pad doesn't respond when clicked. The actual touch function still works, but pressing it in only occasionally registers. I've tried spraying it with compressed air, reinstalling the controller firmware, but nothing works. I would open it up, but the screw holes to actually open up the controller are also incredibly narrow to the point where no screwdriver I have is able to fit.

Any advice on what to do? Anyone else had this issue?