File dialogs bookmarks are not saved and mess other applications bookmarks
1) Save as... or Open... command (file dialog opens)
2) Drag folder from main pane (on right) to bookmarks pane (on left). Folder now appears in bookmarks, and selecting that folder opens it in the main pane.
3) Finish saving or opening a file, dialog dismisses
4) Save as... or Open... again (file dialog opens, newly created folder bookmark is gone)
Expected: Folder bookmark persists forever or until removed after creation. This was the behavior in MuseScore 2.x (with same OS version).
Using version 3.2.3 for Linux in Linux Mint 19.1.