So today and around 3 months ago i got the notification on my github main page that a repository of mine got starred. Going to that repository or their accounts, it seems like it actually never happened. The star count is still at 0.
Now, their accounts seem to be new with no other contributions, so i would assume its some sort of spam protection? I cant tell for sure, since i found 0 information regarding this problem, so it might as well be a bug.