The one before the update on september 30 (ui 5 1).It dosent appear right after the update it took nearly one week.Not updating your phone is better

My s21fe also have the same problem . It was yesterday when i wake-up the first thing i see was the annoying green line on the screen.Immediately i have done a factory reset. But that dosent make any change. After that the fingerprint is not working ...

I am also facing the same issue, samasung should provide free raplacement for green line issue .