XF270HU "After Image" "Image Persistence"

Last night I was playing "Nuclear Throne" which is a very low res game. I noticed there was a lot of flickering but figured it was just normal. I finished playing and logged out. When I came back to my desktop I noticed a distinct "after image" from the game. I could clearly see the residue of my health bar on my desktop. 

Here are two screenshots: https://imgur.com/a/WjJh3nF

The image slowly fades away from view over the span of several minutes. Probably 10 minutes or so. If I turn off the screen it still persists. I've tried updating drivers on everything from the chipset, to the GPU, to the monitor in device manager. It still happens. Is this a hardware issue or is this normal behavior?