I had the same problem with 2016 GLE 450 AMG, (bought new from the dealer) The first week I received it the car would completely shutdown I would have to open the door in order to restart it, for 4 years I had nothing but problem after problem, mostly electrical. They never found the issue with the engine and entire ignition and computer system shutting down and having to be restarted. This had nothing to do with the eco engine start and stop.
The transmission from day one was beyond jolty. Eventually the car completely shutting down stopped after the dealer had done updates to the cars computer system etc.., but they could never diagnose many recurring and new issues. I sold the car as I deemed it a complete lemon from day one.
All that being said I fell in love with the all new GLE 53 AMG when I first heard of its announcement and even considered many full M competition BMW vehicles and Range Rovers etc....,
The New GLE53 AMG, is beyond impressive and works wonderfully, the car is mind blowing and drives 1000 times better then the older GLE's (2019 and older).
Everything is new on the car from what I understand and it is an amazing vehicle.