Galaxy A03s proximity sensor

JohnJaques

My partner has had a Galaxy A03s for approx 18 months.  She keeps complaining to me that the phone's screen goes blank (times out) just a few seconds after the call connects.  It does this even when the phone is on loudspeaker and placed on her desk.  I suspect that the proximity sensor is to blame or faulty.  There is nothing in "settings" on her phone to adjust or reset.  Does anyone have any suggestions?  In case it helps the phone is on One UI Core version 5.1 and Android version 13.

Thanks in advance. 

PHK

There are two possibilities I know off

A screen protector that is covering the proximity sensor. Or a case.

Some of the more modest phones don't have a proximity sensor but instead rely on a change of light in the front camera.  Not sure if that is the case with the A03S