HDR turns on automatically in games.

Hi all.

I have a benq ex3203r monitor. Great bit of kit, however HDR sucks.

HDR is turned off windows side, but whenever I open up a game the monitor auto switches to HDR mode. I can't switch it off on the panel osd as most options are greyed out.

I cannot not for the life of me figure out how to stop it.

EDIT; even games that don't support HDR make the monitor turn it on, ie Hell Let Loose.

Thanks!