"Waiting for: X" when loading saved games

[Nash]

Sometimes when I try to load a saved coop game, it shows "Waiting for: X" where is X is either 1 or 2, for a 2-player session. It seems to be inconsistent to reproduce... sometimes it happens, sometimes it doesn't. Usually if I see this message, just having both players quit the session and try connecting again will produce a chance for the message to appear or not. What does the message really mean?

Also, this is based on testing netgame on the same machine (2 instances of GZDoom launched, one with -host 2 and the other with -join localhost).

I'd like to know what the message really means and if it's an error in my mod that can be fixed by me.

[EDIT] I notice it has a higher chance of happening if I launch the 2 instances of the game too fast. If I launch the host first, wait about 2 seconds in real life, then launch the joiner, the message has a much reduced chance of happening (but can still happen).

[Marisa the Magician]

Sounds like some sort of race condition happening there.