Try retraining FaceID without glasses/headwear, when standing up and holding the phone in front of your face at similar height. Anecdotally, it adapts better to

Try retraining FaceID without glasses/headwear, when standing up and holding the phone in front of your face at similar height. Anecdotally, it adapts better to sunglasses/etc. that way. Also when it fails with sunglasses, and ask for password the first time, immediately logging in with passport will make subsequent unlocks with sunglasses work better (presumably it marks that face adaptation as "correct").