S21 Ultra White line dead pixel

[TooKrazy]

 Hello, this white line with dead black pixel suddenly appear on the phone. The screen still works. what cause this? is this manufacture defect?

[xSteveuk]

Hi,
Try contacting support
https://www.samsung.com/uk/support/contact/
If you still have warranty on phone
Explaining the issue with screen

[Jpswain696]

See if the problem persist in safe mode

See below

https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/.
If it continues its a hardware issue & Samsung will take a look under the warranty