notes stop working after instal ios 16

Tap and hold the Notes icon in Home screen.

Tap Remove app

Tap Delete app

Go to App Store, find Notes app

Tap the cloud symbol to re-install.

Check Settings, [your name], iCloud that iCloud Notes is turned on.

Check Settings, Notes, Accounts that NO OTHER account has Notes turned on.

Restart the phone.

Check Settings, [your name], iCloud that iCloud Notes is turned on.

If still "not working" tell us what that means exactly