Chosen Solution
It is the weirdest thing. At first I thought it was a software issue but it won’t work on any version. Apparently my MBP won’t wake the screen up after opening the lid when the backplate/lid/cover is on. Any ideas why?
Very odd! Apple uses a Hall Sensor which detects the magnet when it comes close to it. This fires off a circuit to disable the backlight enabling the lid down signal which then turns off the backlight. Here’s the sensor which is on the back side of the logic board
If you slide a magnet across the the top of your uppercase just in front of the USB-C ports you should see the display turn off as you pass across the sensor just on the other side. So why would having the bottom cover make a difference here? The only thing I can think off is someone stuck in a sharp knife to deep damaging the logic board where the Hall sensor is located. At this point you’ll need to pull the logic board fully out to inspect the edge area for damage.
