Like the previous comment, you probably have some inside the button. The dirt can limit button travel or contact of the switch itself. TronixFix has a quick video on how to clean devices like this without disassembly.
Essentially, you just spray some BW-100 (non conductive electronics clean that evaporates quickly) and pressure the button repeatedly to work the dirt out.
I’ve linked his YouTube short on how he cleans an Xbox controller button with it.
https://youtube.com/shorts/XxGJuw5vOno?f...
just now by Ian Brown
crwdns2934105:0crwdne2934105:0
crwdns2934113:0crwdne2934113:0
crwdns2915270:0crwdne2915270:0
crwdns2889612:0crwdne2889612:0
0