Yes, same problem here (downloaded iOS 16.1.1 today and hasn't worked since then). I'm very upset about this - the camera hardware button was the reason I switched to Apple in the first place, and has been the reason I don't want to upgrade my phone. I often wear gloves or only have one hand free - could still take pictures, thanks to the camera button. Now all that's gone, thanks to a poor update. I contacted support who tried to give me the impression something must be wrong with my phone (even though I sent them the link to this thread).
I'm really, really hoping this will be addressed in a future update - but I'm not confident that it will, as Apple obviously prefer people to buy new iPhones rather than keep using the old ones. Very angry that it's not even possible to go back to the old iOS version.