my iphone 11 is not updating. any clue as to why

Update iOS on iPhone - Apple Support

If your phone is currently on iOS 14.7, there's a good chance you had been on Beta at some point. If that is your situation, you need to remove the Beta profile by doing the following:

Go to Settings on your iDevice and tap on General. Tap on Profiles & Device Management. Open iOS Beta Software Profiles and tap on Remove Profile. Enter your Passcode if required. Confirm the action by taping on Remove. Power off your iDevice by holding down the Power button, and then slide to power off.