Google Photos untagged faces from all my photos

[Ron-F]

Recently, I found out that my People's album lost all the tags. It took a while to mark all those faces and I would rather not do it again. There are a few people with the same problem complaining at the Google's forums — Google says it is looking at the issue — but the lack of awareness of the problem suggests it is not much widespread. Does anybody experienced the same issues? If so, any solution?