I opened mine up and rebuilt it, padding the pc board to the plastic.
The issue is when the buttons contacts on the pcb oxidize, so you push a bit harder, inadvertently, pushing the pcb into the plastic, and dropping the whole thing down.
mine still isn't 100%, really need to poly pellet the thing up, but its a straight forward fix if you have a flat head, contact cleaner and a small bit of gaffa.