We have been unable to upgrade our Azure classic cloud services to Windows Server 2019 for a few months now.

The matter is confusing because the same nuget package works fine on a regular Windows Server 2019 VM.

Turns out that the OS Image of Windows Server 2019 used for Azure classic cloud services specifically turns OFF TLS 1.0 and 1.1, and only has 2.0 enabled.

Once, we turned on support for the previous versions, we were able to get Mongo connectivity back and everything works.

Now, we have a startup script which enables the older TLS versions on Windows Server 2019.

Please support TLS 2.0 for customers so we can use it.

This is .NET 4.8 on C# on Azure which is a Classic ASP.NET Web Api application.