Why does the build log not capture all standard output?

Question

we're running nightly regression test builds with TeamCity Enterprise (9.1). These are tests written in C# using SpecFlow (1.9.0), Selenium (2.48.2) and BrowserStack. We use MS Test 2015 as test engine.

Now the problem. We have noticed that output from calls to Console.WriteLine() in static methods do not show up in the TeamCity build log. These static methods are for SpecFlow hooks BeforeTestRun and BeforeFeature.

What can I do to have all standard output captured in the build log?

Thanks in advance.

Markus