azure devops artifacts save Nugets to feed as backup incase nuget.org will be down

we want to keep the Nugets we use in our feed in case nuget.org will be down. Under NuGet.Config we did:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
    <clear />
    <add key="Nugets" value="https://pkgs.dev.azure.com/<ourOrganization>/<ourProject>/_packaging/Nugets/nuget/v3/index.json" />
  </packageSources>
    <packageRestore>
        <!-- The 'enabled' key is True when the "Allow NuGet to download missing packages" checkbox is set.
             Clearing the box sets this to False, disabling command-line, automatic, and MSBuild-integrated restore. -->
        <add key="enabled" value="True" />
    </packageRestore>
</configuration>

Now if I go to the artifacts -> Nugets I can see some of the package, appear as NugetGallery, but not all of them. For example Newtonsoft.Json is missing. Also when I look at the source - why are all of them under Nugetgalley, and not 'this feed'?

Thank you for your help.