Multiplayer Lobby wont start (sometimes)

Hello,

So I run a multiplayer dedicated server and set:

-has race director: no
-has broadcaster: no
-max grid, max players, max player count: 26

If the lobby then gets over a certain amount of drivers - the host can't start the session and only get's a failure like "you have to chose a broadcaster and race director". In the first step it is not active and even if you choose one braodcaster and race director. You are not able to start the race?!

So what are things to look into and how to fix this?