Idk why it happened, i never dropped this or anything. The line just appeared all of a sudden this morning when I woke up 😢 someone said that i might have stuck my phone while sleeping but impossible cos I always put my phone on the bed side table. Searched an answer on Google and found out that I am not the only one who has the same issue.
Bring this to a Samsung Service Center. If you have no physical damage this will be done under a manufucaturer defect, ask for a warranty appeal if you are out of warranty. They replaced my S20 Uktra screen after 8 months out of warranty and Samsung acknowledged the issue.