I am using MacOS High Sierra with Microsoft Edge Beta 79.0.309.51. Its an amazing browser
However, I noticed that when a file download fails, it stays in my computer as "unconfirmed download file". This file cannot be deleted from my system by hitting the Delete button manually and throws an error saying "They cannot be deleted". It cannot be deleted manually even after I clear the specific download thread from the Edge's download list.
The files are only deleted once I hit "Clear All" from the browser's download page. This is very annoying as this leads to deletion of all the other download files.
Okay, it's about the time for Microsoft to release version 80 to the beta channel because version 79 is in stable channel on chrome, maybe that will fix this issue. mean while you can try clean reinstalling Edge or try higher channels