I see Unknown tags about every flight now. It’s been getting worse over the past week. And it can just be the only other thing in the sky in a remote location or one of dozens of other players in the sky.
Then there are some that seem stuck? I saw the same player sitting in the exact same location besides the runway (in the trees) at St Barts for days. It’s hard to believe he left his PC on with the plane sitting there for half a week.