Thank you for reaching out to us.
Bu, in the “Media” section it tells me in the “Uploaded to” column that these files are unattached. This is not accurate as they are attached to download entries via your plugin.
I carried out a test in my dev site and it works well for me. This is what I did to prove that it is working for me.
1- I uploaded two different files. One file zipped and one image file via Add New in the Downloads admin section of the plugin.
2- Added each upload to a different Add New. In other words I now have two downloads added to the plugin ready to be added to a post or page via a shortcode.
3- I checked Media -> Library and both files display the Detach option. This means that both are now attached.
As you can see from the steps above it works for me. You might have a conflict somewhere in your site. Please try the following troubleshooting steps.
https://simple-download-monitor.com/forums/topic/test-for-plugin-and-theme-conflict-before-posting-an-issue-or-a-bug/
Let me know how you go.
Kind regards.