Grabed stills have attenuated highlights

I must have some setting wrong somewhere, but I've noticed that if I grab a still from the viewer, it's saved with the highlights squashed a bit. Happens every time.
I'm stumped.
Anyone know what's going on here?

Thanks.

In Project Settings -> Master Settings, what do you gave set for Optimized Media and Render Cache?

I just have ProRes 422HQ, and I don't see any difference between a still and the original image. It's 100% identical on scopes and on the display.

What are your timeline settings? I'm only using DaVinci YRGB Rec709 Gamma 2.4, nothing fancy, and the stills are fine.

Hi Marc, thanks for replying.
For Optimized Media and Render Cache I have ProRes 4444-HDR
Timeline: Same as you - Davinci YRGB Color Managed Rec.709 2.4

Would the Prores 4444 compress the highlights?

Marc, thanks again for replying.

I figured it out. I had put some stills on the timeline and grabbed them into the Gallery. They had their highlights reduced already for some reason and I just hadn't noticed.
Tested with my own footage and all good.

Thanks again.