You notice in a subsequent network trace that the DSCP value is 0x00.
For example you have two adapters with one in production and the other for a private network (maybe used for backup).
You would notice that the DSCP value gets tagged only on the traffic from the production adapter and not the backup adapter.
If you need to DSCP values to take effect on the adapter which does not have Domain access, you need to add the following registry on the system:
Name: Do not use NLA
Create key "QoS" if it does not exist.
After you create the above registry key, you need to reboot the computer.