Non-logged visitors do not have access to files

Non-logged visitors do not have access to the files. Instead of them a window to log in is shown and duplicates (pic. no. “2p” in attachements).
All settings are correct, although the problem is still not solved (4p, 5p). I’ve searched the solution almost everywhere. The 1p attachement shows the correct form of the page (it appears when I log in).

I use Avada theme 5.3.
Probably I do not use any other plugs that can cause this problem.

I am looking forward to your quick response.
Thank you for your help!