There seems to be an issue with races that have preassigned starting grids (so the session itself is only practice and race). If you have ATVO open when the session switches to race it lags terribly, and after restarting it seems to lag more and more over time. I've also noticed that in those races under the sessions tab in the timing screen, there will be a large amount of qualifying sessions with a -1 session number, which might be contributing to the lag

I'll try and get screenshots and a telemetry recording during a race later tonight to help debug the issue.

Thanks Zack. If you got a recording of this issue I would be very interested. I've been hunting this but couldn't reproduce it so far. Do you know how this server was setup exactly?

I had a similar issue. Server was setup as Practice & Race Only with a preset grid.

I'll get a recording tomorrow, I wasn't able to be there for the race on Sunday.

Thanks. We've found the bug and it will be fixed in the next stable release soon. I don't really see how it could introduce a lot of lag but at least it will help a bit. Please let me know if it fixes your lag!