Not sure if this helps you, but Apple rolled out an ``Bug Fix´´-Update to fix the Touch Issue with the iOS 11.3.1 Update. Still the problem with the Ambient Light Sensor persists since it's magically married to the screen and the phone it was equiped with. Once you change the Screen it decides to stop working. If you replace the screen while the phone is not turned off it might work but till you restart the device. Also once you start/restart the device with an aftermarket screen the key inside the Ambient Light Sensor (short ALS) gets void and needs to be re-programmed through an Apple Tool/Machine which they don't do since they only re-programm their own screens only. So your best bet is either to wait for Apple to roll out another update to fix this issue, or life with the fact that you now can't use the ALS anymore. You could also start suing Apple since this is against the Right to Repair law and has nothing to do with security or what so ever like they claimed with the Touch ID back in the days and still do up till these days. But hey if you ask me, if Apple continues doing things like these, I will start buying other manufacturers products since this is pure BS.