maybe its just my setup. I shared a file via file manager, went to to file share , right clicked on my URL for the file and copied it, pasted that into a browser and it repeatedly prompted for a user/password. I noticed in Chrome it would just prompt for user/password. In Firefox it would say "leave username blank and just enter a password"
I hadnt set a password on the file. It wouldnt accept any password I'd give it or even blank.
It's possible its my server..who know but its broken for me.