PSE15 Facial Recognition - Not all groups usable.

I have just installed PSE15. It has been analyzing the the facial recognition software for some time. It has been at ~57% for some time and progressing very slowly. The is 50,000+ photos in my folders, so I guess it will take some time. I have been naming, correcting and grouping some of the grouped faces as this progresses. After naming the faces, there is 3 of about 20 faces that I cannot select and view the grouped photos. I select this group and PSE has no response. Most all of the other groups function fine.

Any suggestions?