MassAI ZoneGraph Vehicles stuck in corners

Hey,
I’m trying to get a traffic simulation working, using MassAI, the traffic pluign and Zonegraphs. My vehicles keep getting stuck in corners and I can’t manage to isolate the problem.
It’s not only the order radius. It seems like it works better with less cars. The cars always stop before a transition between twi ZoneShapes (they are connected, the triangles are white)

Any more ideas?