Screen dims twice when changing image windows

Current computer is ~1 year old. No issues until 2 weeks ago. I will open several images, change the size of the one selected, save it, then close that file to go to the next one.

Now, when I close the file, the screen blinks off and on twice before opening the next file.

I have reset all tools. Running latest version of everything. Intel graphics card.

PS works okay but the blinking is an aggravation.