Dunno if it still happens, but getting a lobbies to remain invite only was something of a black magic trick for a while there. Can confirm this happened though.
Weird. Are you on PC? I remember cheaters doing that on PC I think
Also, how’d it present? Did people suddenly appear without the “x joined” notification?
I wonder how it works, code wise. From what I could tell, it was peer-to-peer and to join a session with others, it would do the cloud animation