We have to research how LCD panels are made. There could have been pressure in that area and now that it's in a warm spot the plastics have had time to flatten on and relieve the pressure in that spot.
I see this effect by apply light pressure on almost any LCD so to call the pressure effect a defect would be writing that all LCDs are defective. If it cleared after a few days, your choice to attempt a return. Not a sign of impending doom.
Hi. My monitor is GB2488HSU IIyama.
I bought monitor 2 weeks ago. In first few days i noticed weird smudge on a screen:
( not my screen but the same symptom ) . I dont have camera to make screen. I was tried to remove this by finger but not helped.
But. When i went away few meters to rest in bed it looked like this:
Anyway it dissapeared itself after 5-6 day of use. Now i cannot see this. ANd question. RMA monitor or not? Why it dissapeared? Keep monitor ?