This is not Flexgate though. [link|https://support.apple.com/13-inch-macbook-pro-display-backlight-service|Flexgate|new_window=true] described by apple as
* Display backlight continuously or intermittently shows vertical bright areas along the entire bottom of the screen
* Display backlight stops working completely
In this issue we have one discriminative symptom:
* Screen works only when lid is 30-50% opened. When fully opened it's either horizontal lines or stuck image.
It should be a ribbon cables retracting issue.
We had it on MBP 2019 - horizontal lines when lid opened >30%. Replaced the display and it went away completely! But guess what.. after 2 weeks it started to show up on the new display. That is frustrating. I can't replace displays on my Mac bi-monthly :(