So I've been doing this for years now, as a Youtuber I take an image file from File Explorer (Windows 10) and drag it over to upload the thumbnail to Youtube. But for some reason the last few days I can't drop the file, it just stays there with the mouse when I let go of the button. On a random page it should let me drop the file and show the image but it doesn't, and it also won't drop if I try a google image search. I have tried this on Edge and Chrome and the problem only seems to exist on Firefox. [My screenshot button hides the mouse in pictures but it's attached to that blue semi-transparent square, trying to drop a file but can't.]