iPhone 13 Pro Max Flashlight no longer working and randomly turning on after backplate was fixed at 3rd party service shop

went to go fix my iPhone backplate at a 3rd party service shop. When they finished repairing the phone. I checked all functions expect the flashlight. Now I believe they broke it but I want to cover all my bases is there anything wrong if my flashlight is no longer working and randomly turn on when I’m not even touching the flashlight button or in camera mode. Only way I can get it to turn off is by hit the back and it turns off for a little while.