A lot of Samsung flagship series phones especially S20 line has been affected by a bug due to which the screen turns white and green leaving the device useless. 
This issue has been experienced by a thousands of users around the world. This issue could be due to their updates or incompetent Exynos chips. 
They are not acknowledging this issue and have to refused to help users affected by this issue.
This might be one of their marketing strategies to leave their 1 year old expensive phones useless so that consumers can buy new their new flagship expensive phone which they launch every year.
Apple has done it in the past by slowing down their old phones via updates and now Samsung is also ruining their one year old expensive flagship models via updates!
This needs to be addressed by Samsung, they should apologize and fix the affected devices at their own expense!