Folder layout issue

[julia-sprenger]

For version 1.3.0 on Windows 10, it seems the folder layout in the right panel is not working correctly as it is not possible to add a file into a folder, but instead all folders (and subfolder content) are always displayed on the same level, see

Also selecting a folder and adding a file in a folder via the Upload button lead to the new file being displayed on the top level.