Bug: People aren't tagged after being recognized

Analyze Clip for People will often recognize people (and will save the recognized people in the People database), but fail to update the "People" metadata for the appropriate people and clips.

I have a vague impression that this happens less often when analyzing fewer clips at once, clips with fewer people in them, or clips with fewer "wrong" identifications, but I can't identify exactly which circumstances will cause the metadata to be updated or not. It seems fairly random.