Any recent damage? Any recent falls?

Normally, it is internal hardware damage.

Screen repair or new protector?

Normally this means your phone got hit somewhere if you dropped it.

If you had a 3rd party screen replacement this is apple's hardware DRM.

Yeah but like a 3 weeks ago? Could that be still an issue

who knows. where did you let it repair?

Not true, screen replacements don’t affect FaceID functionality. They did very briefly when the 13P was released but they quickly rolled back after it got major backlash