I did an update from Umbraco 7.3.1 to Umbraco 8. I follow all the intermediate steps and got the site working after some data migration and code fixes.

I have a /media folder with a Web.config that looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <httpRedirect enabled="true" destination="https://mymediacdn.com/media" httpResponseStatus="Permanent"/>
    </system.webServer>
</configuration>

In Umbraco 7, I could go to the "Media" section in the backoffice and upload a file. That file would be uploaded to my media CDN with no problems.

Now, when I try to upload a file I don't see my file uploaded in the CDN. The files are being uploaded, but directly into my /media folder. However, when I try to download the file using umbraco, it redirects me to the CDN, but of course the file is not there.

My question is, what do I have to change in Umbraco 8 to upload my files into the CDN like I did in Umbraco 7. Why does it work when I download but not when I upload a file?

Note: There is no error in the logs or in the page after uploading the file. It justs says "Media saved: Media saved without any errors".