New folder only visible after browser-refresh

A newly created folder will only be visible in the sidebar when a browser refresh is carried out.

I was a bit confused and search around because I was able to select and assign the new folder in edit mode. In the sidebar it was only displayed after a browser refresh.

Edit:
Browser Firefox

Edit 2:
Empty folders are never shown. Drag and drop an item into a folder can only be carried out if an item has been added to a new folder in edit mode and a browser refresh is then carried out.