Vibration intensity is not consistent

The iPhone 14 PM is really giving me headache.

I already had a lot of missed calls because the phone doesn’t vibrate during silent mode.

vibration on, haptics setting max on bar etc

yet when the phone manage to vibrate after restarting, I notice another issue. Tested by calling myself, When phone is facing upwards vibration is subtle but when phone is facing downwards the vibration is intensify . The strength is similar when you click on preview under ringtone vibration.

it is really a nightmare experience. I can’t imagine how a new phone is creating so much inconvenience to my everyday life