We have a Artifactory remote repo which is pointing to https://www.nuget.org/ and we are able to browse some of the packages. which are only getting downloaded to the package directory when we do the dotnet build.
For example we are getting an error Package bootstrap.4.5.0 is not found in the source.
Also when we browse the remote repo from the browser, we are able to see the version bootstrap 3.0.0 only and new versions are not reflecting.