Same faces not getting stacked in facial recognition

I'm just starting to use facial recognition. When I run it on a large group of photos, it doesn't stack the images. I identify people and select Find Similar Faces and it also doesn't work. I think I'm not doing something right, but not sure what it is. I'm wondering if it is an issue with indexing. Thoughts?

I'm running Mac Ventura 13.7.4.

Thanks

David