When I start up using the power button, the screen has green lines and a green Apple icon. It may start up, but it may automatically shut down and restart. It will work fine, but if I shut down, when I restart, the issue happens again.
MacBook Pro 16″, macOS 11.3
I agree with lobsterghost1, but first try resetting the NVRAM of your Mac. It may fix the issue - Reset NVRAM on your Mac - Apple Support
If it persists, take it in for service - Find Locations - Apple
I'd hazard a guess your screen is failing and you have a hardware issue. Schedule an appointment at your Apple Store Genius or Apple Authorized Service Provider for service options.
vertical lines are most often used by issues in the display component itself, not in the system mainboard.
To obtain service, you must swear that you have a backup. If you don't already have one, now is the time, and we hope it is not too late.
What does a green apple logo mean at start up?
