Did you remove / smudge the camera lenses when removing the back glass? You should give the camera and inside of the rear glass a good cleaning with a microfiber / lens cleaning cloth. The LiDAR sensor might be used to aid in the focus of the camera, so if it can't "see" through the back glass that could be a problem.
Do you have pictures of the damaged ribbon cable? It's possible that it carries signals necessary for camera operation along side power for the LED.