I am a student who received a Samsung Galaxy Tab A6 tablet from my school 2 months ago (with Android 8.1.0)
And after a week of running it; I noticed a green stuck pixel that appears on blue and some black backgrounds.
My stuck pixel is a bit weird because it appears with like 15% opacity when only Samsung Knox Manage app is running, and it fully appears when I run another app with Samsung Knox Manage.
I have a feeling that Samsung Knox is the reason of this stuck pixel, but I can't close it because my school manages my tablet remotely through it.
I have also tried the stuck pixel solutions and apps but nothing worked.
It also doesn't have a warranty :/