I recently switched from Windows 10 to Ubuntu 20.04 and noticed that unlike in Windows, drag & drop of mail attachments does not seem to be possible in Ubuntu. I don't get any error message when trying to drag & drop an attachment, e.g. onto my desktop. Just nothing happens. This adds quite some overhead to my workflows - especially when I just want to upload an attachment via browser. In Windows, this was possible by just dragging & dropping the attachment from Thunderbird to my browser's file upload. Now I always need to download the attachment first before I can work with it on my file system. Is that a known issue that can be fixed somehow? Any help is greatly appreciated.