iPhone locked with correct passcode

This morning after turning off my alarm, my iPhone refused to use FaceID, so I put in my passcode and it also got refused. I tried restarting it multiple times but without success. I'm currently stuck with my iPhone unavailable. I know I'm not crazy, the passcode is correct. It worked fine yesterday. I also have an Apple Watch SE (1st gen). Is there any way to unlock it using the watch?

I don't want to do a 'Erase iPhone' as I do not have a recent backup made. Is there a way to backup my iPhone while it's locked?

I've found articles online that mention this happening after an upgrade. I can only assume there was a new version released last night and automatically installed (as I have this option enabled).

I'm using a iPhone 12 Pro Max.