Chosen Solution
There’s a hinge held by two little screws and thin metal rod on each side of the headphones. Over time, one of the hinges has broke. I have been unable to find a replacement piece and can not find anyone with the same problem.
If you are taking about the hinge at 3:40 seconds of this guide, it appears it is just a pin and socket and the plastic pin may have broken off: https://www.youtube.com/watch?v=4oPiRWQT…
