GLE400 Start Stop Issue - Car not starting back up

So I'm asking this for a friend that resides in Hong Kong. He has some issues with the start stop of his car. It does not happen always, but occasionally when he's at a light and the car engine stops, sometimes it doesn't turn back on. The start stop feature just suddenly stops working. During those times, he has issues with starting the car by pressing the engine on/off button as well. There are times when he's at a light stuck for a few minutes before he can get his car to turn back on.
He has brought it back to the dealership in HK several times and they could not find anything wrong with the car. Battery was changed, but didn't help the case. I was wondering if anybody have any idea what the issue might be.
Thank you!



