Try renaming the file from download 6.png to download_6.png to bypass the problem but I guess someone should check why a filename with a space fails

Edit: Just saw your other issue, follow the instructions from @PhilETaylor

space or not is the same. For exemple this url is the same:
administrator/index.php?option=com_media&view=file&mediatypes=0,1,2,3&path=local-images:/articoli/2021-09/img_20210906_105007.jpg

I click on "media", click on the "pencil" of a photo and log out.

How do you logout? There is no log out link/button on that page?

If I logout in a different tab, and then come back and refresh this page Im then at the login page and then I can login with no issues.

How do you logout? There is no log out link/button on that page?
after clicking on the pencil I automatically see the login page and the session has expired.
Please note that I have never seen this screen in my life.

Ok thanks.

Are you using CloudFlare or Siteground services?

@galamarco , please see above request for information on your issue.

Are you using CloudFlare or Siteground services?

Yes I'm using CloudFlare

I'm facing the same problem

Have you followed the advice from cloudflare to the exclude the admin

https://support.cloudflare.com/hc/en-us/articles/201997250-Cloudflare-and-Joomla-Recommended-First-Steps

I am facing very same issue, have no idea what is going on as on the same server I have joomla 3, with joomla 4 whenever I try to rename file I am logged out and the path looks like this
https://.../administrator/index.php?option=com_media&view=file&mediatypes=0,1,2,3&path=local-images:/powered_by.png

@swilski are you using using CloudFlare? Is this still an issue?

Have you followed the advice from cloudflare to the exclude the admin

https://support.cloudflare.com/hc/en-us/articles/201997250-Cloudflare-and-Joomla-Recommended-First-Steps

I am closing this as there is nothing further to do except for the users to follow the advice from cloudflare