Why does my volume up button not work?

I recently bought an iPhone 11 and discovered the volume up button no longer worked. I replaced the flex cable assuming that was the issue to no avail. The silent button and the volume down button works which is what I found to be the most confusing, even on a new flex. My next guess is the WiFi flex that it connects to may be damaged in some way, although the WiFi also works perfectly fine and connection to the mother board looks fine also, no damage or flex pinching. Any ideas would be really helpful as I'm almost out of ideas, thanks!