I seem to be having the same issue. I have a lobby map, an empty transition map and a gameplay map. Each with game modes with bUseSeamlessTravel = true. When executing the seamless travel, sometimes it works, sometimes it fails. The times it fails it always involves the client getting stuck in a separate version of the map with unmovable camera and no pawns (as OP said, limbo). Interestingly, the client that gets stuck is always done loading way faster than the server who is still loading the new map. I will spend a bit more time to try to make sure its not an error on my end, or perhaps a work around for it. But if that fails I’ll try to reproduce this in a simple project too.