dotnet build failed due to remote nuget source

I am working with .Net 8 projects. They are in solution. When I build solution from IDE (Rider) everything is fine, all packages are restored, build is successful.

But when I do the dotnet build I'm getting error:

error NU1301: Failed to retrieve information about '{{package_name}}'from remote source '.../index.json'

I can access that source using VPN only.While doing build - I'm connected to that VPN.

I've also added packageSourceCredentials to nuget.config where remote source is declared.

What should I add/try to make it work?

Why I need to use CLI when I can build in IDE? I need to update database using EF Core and migrations... and issue is the same for both cases.