Well in our site builder I couldn't see any modules that said there was a BBMD assigned but I didn't have the tech on site check the modules for a record. This is a possibility.
I would have liked to do a capture but they decided to skip that and went with the sure thing and made the trane system go to port 47908 which solved the problem.
For the integration points between the two systems we took our module and put it on ARCnet to connect to our system, then took the BACnet/IP port on the same network but on 47908.
Expressed opinions are my own