Headless chrome window / tab switch does not work

I ran into some trouble when running my tests in Chrome Headless.
After I make a WebUI.switchToWindowIndex(1) the following actions (e.g. waitForPageLoad) time out. This happens ONLY for headless chrome.
Via getWindowHandles I can see in my logs there are 2 windows, and I can see that after the switch the new window is indeed the new windowHandle, but for some reason there is no action possible afterwards. Each WebUI action times out, cannot even take a screenshot…

In chrome (non-headless) I also noticed that WebUI.getWindowTitle() did not provide results after WebUI.switchToWindowIndex(1). I need to use WebUI.getUrl to go and verify the url of the new window.