TaxiwayParking breaks when T-Positions are added

When additional T-Positions are added to a TaxiwayParking, the next time the project is opened, the Parking spot is not diplayed and shows an error (not connected to two points) and the Boarding_Stairs are connected (dashed line) to the ARP.
Error can not be fixed in the Editor.
Only removing the teeOffset Attribute in the XML fixes the Problem!