Volume up button not working correctly

Hi,

I have a Fairphone 2 with a Slim case. The volume buttons are not really good to press. Sometimes there isn´t any haptic feedback but they will still work. However most of the time the volume up button does not work at all (unless it is pressed very hard).

I already removed the cover and tried the buttons without it. They work perfectly fine. So it has to be an issue of the case.

Does anyone else experience this problem? Does someone have a case without these issues? Should I request a new case?

Thank you!