The infamous green lines have come back to haunt some Samsung smartphone users and it seems that they appeared for most people after updating their phones.
Some affected users claim that vertical green lines appeared on the screen after a software update. This does not mean that it is a software problem and can be fixed via an update. It is possible that an underlying hardware defect was exacerbated by the update and manifested itself as green lines on the screen.
Although green lines are a fairly common problem with OLED displays and have also been seen on phones made by other companies, including Apple and OnePlus, their cause is still unclear.
Samsung previously said these may be dead pixels. Other possible causes include a damaged or loose screen connector, incorrect configuration, or water or drop impact.
In most cases though, the lines appear out of the blue, and not because of the phone being dropped or otherwise damaged.
TLDR; This whole event has made me deeply distrust Samsung. They do not guarantee the quality of their products (even flagship products) and the entire customer service process at Samsung Singapore has not been streamlined at all. Even though I had made an appointment, I then had to deal with the ridicule of contacting online support when I was just at the service center. They made me lose an entire trip. I doubt I will use any Samsung devices after this and will recommend the same to others unless these issues are resolved. I hope they succeed.” – penguinastronomy
Judging from these stories, it appears that Samsung takes no responsibility for this issue and the only option for customers is to foot the bill for a new screen. Samsung has been offering free replacements to Galaxy S20 users in 2022, so the company may be forced to change its mind if more similar issues are reported.