My iPhone Face recognition not working!

My iPhone XS with software 13.4.1 suddenly stopped face recognition! And when I went to settings, face recognition. I reset my previous face recognition and wanted to make a new one.

but to my surprise, a message (move iPhone higher/ lower keeps coming up and never finish face recognition!

i tried to clean the iPhone front cameras and reset all settings But didn’t work!

anybody knows how to fix this bug?