Actual host names changed, but you get the idea. So, these names don't have .sharepoint.com in them.
We had some issues authentication with PowerShel PnP against these URLs, one of our colleages from a different department is also having issues authentiating using PnP Core .NET library. I can share the errors later, but the broader question is this:
Does PnP Core Library support authentication with credentials (user login and password) against SharePoint tenants with tenants that don't have .sharepoint.com in the URL?