Constant HTTP request timeouts for C# Selenium tests running on TFS server
As you said: Enabling interactive mode (basically an open RDP session) is allowing the tests to be executed.
Another solution: If you run the TFS agent as a Service, then be sure to check "Allow service to interact with Desktop"
This might not work if your application cannot be run as the Local System Account. In that case you must not run the Agent as a service; You can only run it in Interactive Mode. So far I have had good results with the service this way, though.
Note, I had to do this, too: add the "no-sandbox" flag when starting up the ChromeDriver