I used to have the same issue. After speaking with Apple support, they asked me if i have a case and screen protector on my phone. I do have both, but i never thought the issue might be from any of those, i was more concerned about the camera settings and files imported from the backup to my new 16 pro max. So basically, i was betting on that to be the issue. But clearly wasn’t the case.
I had a screen protector fitted on the first day i received the phone, from Flolab, one of the best screen protectors out there. Dropped my phone, smashed the screen protector and decided to replace it with a new matte screen protector wich i got from Amazon ( Ksleri 2 Pack Matte Screen Protector, in case anyone is interested ), instead of waiting for a couple of good days till Flolab sends a new one.
And, surprise surprise, my camera control button works flawleslly now ! No reset, nothing changed, etc. Before i removed the damaged screen protector, tried again, and i had to press twice for the camera control button to register and open the camera. Now, one press and jumps straight into camera.
So if you guys are facing the same issues, i suggest you start with your screen protector, as that’s the culprit. Don’t know how it affects the button, but obviously it does.