This new ExtremeXOS 15.7.1 CLI feature includes processing and forwarding of STP BPDU‘s either by system wide or port based filter installation.
In previous releases this processing and forwarding of STP BPDUs was based only on ports, now this has been changed to system wide (default). Prior to ExtremeXOS 15.7, blocked ports transmission of the BPDU‘s was restricted, but for the Loop Protect feature when any proposal agreement BPDU is received in the blocked port, then reply for the proposal agreement is to be transmitted. Due to this MAC movement is reported and the packet was not processed. This feature prevents this issue.
You can roll back to the previous implementation (port-based) if any issues are encountered .