Black screen of death….sometimes

This sounds like FlexGate! You should get to an Apple Store as Apple did have an extended warranty program for this. You’ll need to fight for it now as you are on the late side.

Basically, every time you open and close the display you stressed a flex cable which suppliers power to the displays backlight. Apple acknowledged the cable was a bit short so the tight pull at the mid point would cause the cable to fail.

Most of the time people encountered uneven lighting of the display at the bottom edge where three strings of LED’s sit to light the backlight. Often every third LED losses it’s power, sometimes it’s two strings or when all three fail no backlight (black screen).

To prove it slightly moving the display once it is getting lit where the ribbon connections are reconnecting them selves and as you move to the mid point the connections will break (think loose lightbulb in its socket)

If they are unwilling after pushing up the food chain of management then you’ll need to do it your self or have someone do it for you. Here’s the needed part MacBook Pro 13" Retina (Late 2016-2017) Display Assembly and here’s the guide Sostituzione gruppo schermo MacBook Pro 13" Function Keys 2017