Randomly kicked back to main menu when hosting listen server

I've had this happen a couple times now..whenever I host a listen server match, it will suddenly quit and take me back to the main menu, terminating the match. This only just started happening..last night I was able to host without issue.

The first time I hosted today it suddenly quit from the lobby after one player joined. On my second attempt the lobby filled up and the match started, but it quit right after the start of the round (immediately after I purchased my skills.)

Yeah, we're trying to find this one. It's an interaction with steam.

I saw this in the log files when the problem occured here:

Code:

Error: Can't start an online game in state 3
DevOnline: OnGSClientDenyClientId:[15360760]  Reason: th[
0
Log: We're a listen server and we failed our own auth!

I have the same error, but can't find anywhere how to solve this.
The server where I want to run the dedicated server on does not have Steam installed. Is that a requirement? Because if so, I can't join on more than 1 machine at once to Steam. So I would have to create another account and buy the game once again. Which I am not going to do.