I've noticed a strange behaviour when making call using my Note 20 Ultra using a Bluetooth headset.
When I am during the call, if the screen goes blank or I hit the lock button, the screen will never wake up until I don't press the lock button, or double tap the screen. Shouldn't be active the pick up wake thing so when I pick up the phone from table to start the screen? This is pretty annoying specially in car. As far as I remember on my Note 9 the screen was waking up when I pick up the phone.
If the call is ended, the screen will wake up correctly, the problem is only during a call with Bluetooth headset.