TLS 1.2 not negotiated in .NET 4.7 without explicit ServicePointManager.SecurityProtocol call

Question

I need to upgrade a .NET application to support a call to an API on a website that only supports TLS 1.2. From what I read, if the application is targeting 4.6 or higher the

Answer 1

I am on Windows 7 and .NET 4.7.1

The recommendation to use Switch.System.ServiceModel.DisableUsingServicePointManagerSecurityProtocols and Switch.System.Net.DontEnableSchUseStrongCrypto mentioned in two other answers did not work in my project and OP's code was failing too.

Reviewing source code for ServicePointManager and LocalAppContextSwitches I came across another config setting which worked.