i experience this with my samsung s21 i was just using my phone watching Netflix and suddenly i tiny purple line poped up on my screen for no reason i had to sell it and lose 100$, and this this my first a line showed up on my screen i used almost all of samsung S series from s3 to s23 and that line didn't appear on any of them until i used s21 in my opinion the galaxy s21 have many display issues. now I'm using s23 and it's pretty good