[jcomis]

This has been happening to me across all google products. Emails - random emails are just gone. Sometimes I can see evidence of them from body of replies. Maps - I am a HUGE user of maps, starring thousands of places as I planned travel over the years. Randomly 1-50% of my stars just won't be there. Sometimes they come back. Photos - same issue as OP in this thread, random clusters of photos (mostly 10+ year old ones) just gone. There are a lot of support threads out there of people reporting the exact problem with no real fixes too.

[wingworks]

I have the same with starred places on google maps. Sometimes they're there, other times they're MIA. Super annoying.