Bug on Arch Linux: Nothing in the "Palette" or in the "Add Palette"

I've been using MuseScore on Windows, and everthing goes well. But on Arch Linux, there is nothing in the "Palette" or in the "Add Palette". But I can actually find everthing in "View" -> "Master Palette...".
I installed it with "pacman".
You can find more information in the attached image below.
What should I do to solve this?
Thank you so much for your help!