Screen Brightness Intensity Changes Windows 10

Depending on how bright or dark the content of my Photoshop file is, my screen (laptop running Windows 10) will get brighter or darker.  This is especially noticeable when I zoom in or out on an image.  Never had this before on previous laptops.

I don't seem to have this issue in other apps - for instance, if I'm web browsing, where the content changes all the time, I don't see the screen brightness change.

Odd thing is that the Screen Brightness is always at 100% (deliberately set) whenever I check it - so it's not like the system Screen Brightness is changing.

I've looked in the Display settings of Windows and don't see anything that would make the Brightness dynamic.

This occurs regardless if the laptop is on Battery or Plugged In power.

Any System or Photoshop suggestions?

Thanks,

Marc