Q10 Pro stuck in HDR mode

[JDiG]

Got my Q10 Pro today, and managed to semi-brick  it in less than an hour :/

So what happened:

I got the box connected to a non-HDR UHDTV. I tried to play a few HDR10 video clips on HiMedia's videoplayer (just to see what happens), and got a black screen of every one of them. Non-HDR video clips played fine.

Then I discovered the HDR setting in the Settings menu. It was originally set to convert HDR to SDR. I selected HDR10, then accidentally powered the box down. After rebooting box outputs all video in HDR mode, including its own menus, i.e. the image is all blown out. HDR settings claim HDR is disabled, i.e. output is SDR. Switching back and forth between the three different options makes no difference; image remains badly blown out.

I even did a factory reset, but it didn't help.

Anything else I can do to restore output levels to normal?

[JDiG]

Okay, managed to restore original settings by re-installing firmware and wiping user settings at the same time. Whew!

edit: Oops, no I didn't. Levels are good when box is outputting 1080p60, but when I switch it to 2160p60, output's all blown out again.

Any advice would be much appreciated.

[JDiG]

Image is blown out only at resolutions 2160p60 and 2160p50. Levels are normal for other 2160 and 1080 resolutions for some reason.