Wirquin shallow shower trap issues of keeping the chrome cap too fit on

[Inverness]

Hi guys any one experience wirquin shallow traps?! Great design.
I’m having an issue for the chrome cap too stay on? There’s three screws where the cap slots in to place but everyso often it pops off.

If anyone has experienced this please let us know how to fix.
Thanks

 

[ShaunCorbs]

Small dab a silicon ?