How can I improve face recognition in Apple Photos

It seems to me that Photos.app under Mojave did a better job of automatic face recognition.

I am not certain but it even seems to me that Photos "forgot" some of the face tags since I upgraded to Catalina.

I have been tagging lots of faces in many photos, but still it doesn't automatically recognize the faces in many other photos, where - to me - the correct face is obvious.

Is there anything I can do to improve Photo.app's automatic face recognition?

Best regards, Gabriel