How to unlock auto rotation on external device

Hello

I have a Pipo X8 which is running 8.1. I currently have this positioned upside down on my wall so that it's at the correct angle to use (it's a small tablet like device that's a wedge shape, the fat side is at the bottom). This will auto rotate so that the screen shows correctly on the tablet, but when I connect (via HDMI) to a TV, the auto rotate function is not supported for external devices and therefore shows the display on the TV upside down.

If I then rotate the display on the Pipo then the TV display rotates too so I have an upside down display on the Pipo and a correct display on the TV, at no point can I mirror the devices so that they are both showing the correct way round.

I really don't want to have the Pipo the other way round as it would be awkward to use and the screen would be angled towards the floor rather than the ceiling.

Can anyone help with how to either unlock the auto rotate function or advise on a way to make them display the same way round ?

Thanks

jarlock