AW3225QF, any refresh rate below 240hz setting will not show true black unless HDR in windows is off

So when I was playing around with my settings because of troubleshooting other things i found out that if i set the monitor to 120hz and Windows HDR is on, it won't show proper black (oled off). So the screen is showing slightly grey (it's not the grey/magenta tint in a bright room i'm talking about).

When i turn windows HDR off it will show proper blacks. Turn it back on and i get the slight grey lighting up on a black wallpaper.

So in summary:

240hz, HDR on = true black
120hz, HDR on = not true black

120hz, HDR off = true black

What is the cause of this, what am i doing wrong? Can't find anyone with a similiar issue.