It does, that's why it measures the music volume before, then the volume is set to zero, then the change volume action is supposed to set it back to what it was.
Here is my macro. I want priority mode to turn on when I start the music app, but keep the same media volume.
Running the action ends in everything being successful, except for the volume change, which the log tells me: "set volume failed - the macro was null"
Testing the change volume...