If you turn "Use HDR" in the Display Settings menu of Windows off it will quit doing it. You'll have to turn it back on when you're done snipping if you want HDR on though.
When using Snipping Tool how to prevent grey background in selection
I've used the Snipping Tool for many years, and just recently when I select to save an image, the resulting image is keeping a grey background within the selected target. As you can see below, instead of having the selected image on its original white background, it's an unintended shaded grey. How do I prevent this from happening?