How to enable hdr on s912?

I have dug through settting in both coreelec and Seren to enable hdr. I find hdr links but my tv never switches to hdr no matter what I select. Can someone tell me what I might need to do?

You don’t have to enable anything, it works out of the box.
Check your tv’s settings, and enable it for this HDMI input with your box.

Maybe try direct hdmi connection from your box to TV, not through your AV receiver, if that is your present connection…