palettes panel shrunk to minimum

Since I own a second display I somtiems move panels to the second do gain more space on the main display. Since that eventually the palettes panel shrinks so much, automatically, that no symbol is shown at all.

That is no big deal at all. It's always possible to resize it again. It only occurs with the palettes panel. I ask whether I do someting wrong to make that happen or is it a glich?

OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 3.6.2.548021803, revision: 3224f34