Brocade ICX7750 wrong VLANs on Port shown

If somebody could explain how the discovery process works (without MIB) I might find out some more information. The strange thing is, that we have lot’s of brocade / ironware switches running in our network, but currently it seems the problem only exists with the ICX7750. So if I had a clue “climb down” the process, I might be able to find out what’s different to my other switches. (Finally it could be an issue with the switch firmware, but updating our core stack just in order to find that out is not the way I wanna go)

Thanks,
Rainer