I am observing black flickering lines on my M1 MacBook Pro screen since the day I have updated to macOS Ventura. I contacted apple support snd they asked to me reinstall the update. But nothing changed. I also did diagnostic test for hardware and had no issue.
MacBook Pro
Most likely there is a hardware failure with the Display Assembly or possibly the Logic Board. Have Apple or an Apple Authorized Service Provider examine the laptop to provide you with a repair estimate to confirm the source of the failure. You can confirm the built-in display is bad (or possibly internal display cable) by connecting an external display and enable mirroring. If the issue only affects the built-in display, then you have confirmed a hardware issue with the built-in display. If the external display also has the issue, then you can try booting from a macOS USB installer.....if you still see flickering lines, then the Logic Board is bad, otherwise it means you have some software or configuration issue with the OS on the internal SSD.
Black flickering line after macOS Ventura update
