Ah ok, yeah we have been seeing similar reported issues by others here: .NET SDK v25.2.0 and 26.0.0 freeze/lock IIS/VS - #20 by pauld
For now, when working with .NET not using Core, you should be able to wrap the SDK calling code with Task.Run(“api_you_want_to_call”).Wait();
We are still working with our SDK team to have a better experience for developers building with .NET framework
Jordan