You have configured DSCP CoS in your network and have applied BA and multifield classifiers...

In Junos OS Class of Service (CoS) processing, there is a specific order of operation for packet classification.

Precedence of Multifield (MF) Classifiers: When both a Behavior Aggregate (BA) classifier and a Multifield (MF) classifier are applied to an interface, the MF classifier takes precedence.

Processing Order:

The BA classifier (e.g., DSCP or 802.1p) inspects the packet header and assigns an initial forwarding class and loss priority.

The MF classifier (which looks at multiple fields like source/destination IP and port) is processed later in the pipeline.

The " Final Word " : Because the MF classifier is evaluated later, its results overwrite any previous assignments made by the BA classifier. Therefore, if a packet matches both, the MF classifier determines the final forwarding class assignment.