Trouble adding faces and face names in photos

This can happen, if you crop or rotate the photo after the faces have been detected.

Undoing the cropping should bring the faces circles back to the correct position. Or add a tiny, invisible retouche to the cropped photo. That will force Photos to repeat the scan for faces for this photo. The incorrectly positioned faces circles will be removed, and if Photos cannot find the faces again in the cropped photo, you can add the faces manually by clicking the + button in the Info for the photo.

Good luck!

If it happens again, consider to send a bug report to Apple, so Apple can fix it in macOS 14 Sonoma. You can use the feedback form here: Feedback - Photos - Apple