If I go to diagnostics everything works except notification vibrations, it keeps telling me to increase my vibration intensity, opens up settings, vibration intensity is already full, takes me back to diagnostics and the loop just keeps going on and ...

Same happened with me. I have A51 and after the update the vibration stopped working for notifications, works for calls and alarms, but for notifications phone doesn't vibrate at all.I have even sent error reports to Samsung but they haven't replied ...