(apologies for not using the correct English technical words for the various elements, please edit my question if this is not clear)
I have a Geberit In-Wall Flush Toilet with two press puttons. One of them started to recently fail (after a few years).
After disassembling the cache, I found that one of the two "screws" which are pushed by the buttons is loose. It would not snap into the vertical positon the other is.
I made a video to make it clear: https://imgur.com/a/XvumtBL
The right screw is solidly snapped in, I cannot turn it when twisting left and right.
The left screw is all loose, I cannot make it keep a vertical position (I expect that it should snap into that position). I pushed quite hard but I get a hard stop.
The screw itself seems fine. One thing which I noticed is that the rubbery part behind the back of the screw head (yellowish in the picture below) lands on the top of the screw when in the "correct" position (which it cannot get into), while the one on the right screw is at the bottom
Where could the problem be? Should I turn it clockwise really hard to snap it in position?