Solved Auto Brightness Setting Present But Not Working Screen Replaced Iphone 6S

Chosen Solution

After replacing the display assembly on my iPhone 6S the auto brightness feature has stopped functioning. The replacement display was a complete OEM genuine assembly taken off of another iPhone so the sensors are genuine. I still have the option to turn auto brightness on and off in settings (iOS 13.2.3) but the brightness doesn’t actually change depending on the light level in the room. I have reset the phone in settings, should I try resetting it from iTunes instead? Thank you, Oliver

Transfer the front camera assembly (FCAM) from the old screen to the replacement screen. The replacement screen probably has a faulty pre-installed FCAM assembly which has an ambient light sensor on it (ALS)