Window size automatically changes
The Musescore window size constantly resets itself when I click on most objects in the score or press Play. So that I can see the entire window, i.e., window maximized, I will double-click the Title Bar (normal macOS function). It will set the Musescore window to match the screenshot where it fits nicely above my dock. However, as soon as I click on most items in the score (e,g., a note or a measure) or hit the Playback button, the window will extend below my screen. I will then have to resize the window again.
I am not sure if this issue is related to the weird artifact where the Mixer and the Play Panel are garbled together. It seems like the panels are not adjusting when I try to Maximize the window.