Hello again,
I cannot remove folders from a collection:
- Add a folder containing subfolders and files as a new sub-collection.
- Try to remove a subfolder from the collection: nothing happens.
- Try to remove the parent/main folder from the collection: nothing happens.
- Try to remove a file from the collection: it works.
Also, the "Remove from collection" option is not available in the context-menu. Only in the Delete menu (where it doesn't work, as described).
When adding as Members, everything works as expected and the context menu entry is also available.