I ordered a replacement screen and frame (screen mounted to frame) from aliexpress. The assembly seems original and...

I managed to make it work by pressing the calibration button in the test screen. Be careful so as the sensor is not covered before starting and during calibration. For calibration: (1) Go to service menu: call *#546368#*710# (2) Device Test -> SAAT -> Auto Test (3) Long press power button -> “Don’t touch proximity sensor” appears in red (4) Press “PASS” (5) You will reach the proximity and light sensor test screen (6) Make sure the sensor is clear and not covered and press “Cal Start” (7) After calibration is done the sensor should work OK