A few years ago I had a 10+ year old LCD start to show pink horizontal lines and it partially blended and distorted 30% of the monitor on the left side.
The interesting part was you could see a decent amount of the original screen's contents even if you had a different screen being shown such as being behind a lock screen. So imagine a scenario where you had your monitor on with something sensitive open, you turn on your lock screen and go AFK. You could come back 15 minutes later and still see a third of whatever apps you had open at like 50% opacity and it blended through with the pink lines and login screen. It was like an acute burn-in effect.
Oh nice. Yeah it sounds very similar. I never did a touch test to see if it was hotter but heat makes sense. The pink lines and distortions were always present once the problem started but eventually the previous image would fade away. I remember trying everything with no change (different computer, drivers, cables, adapter types, etc.) and also chalked it up to a hardware problem.
The interesting part was you could see a decent amount of the original screen's contents even if you had a different screen being shown such as being behind a lock screen. So imagine a scenario where you had your monitor on with something sensitive open, you turn on your lock screen and go AFK. You could come back 15 minutes later and still see a third of whatever apps you had open at like 50% opacity and it blended through with the pink lines and login screen. It was like an acute burn-in effect.
I don't have a picture of it but it was very similar to this effect (I found this when Googling): https://linustechtips.com/uploads/monthly_2017_04/IMG_201704...