Mixer is not refreshed when scores are switched

A bit more info:

Mixer window is the correct one. The window has a title "Parts List"

The problem seems to happen when you've played one score, close it and open another. The parts weren't updating to reflect the new score, so the Mute and Solo buttons weren't working correctly --- because the parts were for the closed score. I didn't realize that's what was happening when I posted the issue originally.

It does not seem to happen consistently. There may be a particular parts change that triggers it, such as going from more parts to fewer, or fewer to more, or something like that. I will post again if I can find a sequence to reliably reproduce the issue.

I am continuing to test this. I have created scores with a variety of parts. If the Mixer window ("Parts List") is open when you close one score and open another, the parts are not refreshed -- the window continues to show the parts/instruments of the closed score, not the newly opened score. This would not be the expected behavior. The correct parts appear only after you close and then reopen the mixer window (palette).

Closing a score should dim or clear the mixer window. It should be refreshed immediately when a score is opened, so that it correctly shows the parts in the newly opened score.