I really don't know why this might be happening, try naming the room.
Anyway, I'll go through the flow to make it clear what is going on...
Firstly it tries to enter a room, as there is none, it tries to create one, connecting to the ‘Game’ lobby, authenticating and finally creating the room ‘’, and that's when it fails, giving you that error. That's why I think the problem is the name of the room.