mh that's weird, because a solid white light is usually a good sign that you're controller is connected and you're ready to play.
Maybe it helps if you try to disconnect your controller again and try to link it again with the screen.
Otherwise it might help if you do a Factory Reset on your controller. After this you have do the WiFi setup again on it, but it can solve some weird problems usually. Here you can find again how to set up the controller.