I have a Hyhundai Hera 10.1 and recently thought I would use my TV so bought a HDMI cable. When I plug this is the tablet screen goes black and the Tv mirrors / duplicates the tablet. Great, but on touching the tablet screen no cursor appears or control. Does the touch screen stop when plugged in? Do I need to keep the screen on so the touch sensor works. Thought it would plug and play. Used a couple of apps to keep screen on but on plugging in lead the tablet returns to the same fault/setting. All threads appear to show how to turn screen off but not about the touch pad. Any help advice will be warmly received.