xUnit with WebHostBuilder and POST Method

[Michael]

I have a unit test that uses WebHostBuilder to simulate an HTTP POST method against a .NET Core 2.0 WebAPI controller.  The test works and passes when I execute in Visual Studio but it does not pass in Pipelines.

I also use WebHostBuilder and HttpClient for a GET request and that passes in both VS and Pipelines.  Any suggestion as to why is appreciated.

Note this is a Docker project and the test image I am using in Pipelines is microsoft/aspnetcore-build:1.0-2.0.  I am unclear if that affects anything or not.