[iOS, labs] weird header styling changes when serving the app

When I generate a fresh ionic app setup (angular), the styling of the header gets all messed up after refreshing the page whilst running the app in ionic labs. When I run the app on an iOS emulator device, the header is also without the proper styling. See this image:

See this link for a video example. Can anybody tell me why this happens? Notice the header in the iOS device… The weird layout shows after a full page refresh.