MBWorld.org Forums - Transmission issue

Hi everyone! I'm a W166 2017 GLE 43 SUV (with 9 speed transmission) owner. I had a bad transmission issue last Sunday night. My car's transmission was stuck in 3rd to 5th gear at first. Then I pull over and restarted the engine, since then it stuck in the 1 gear and doesn't upshift. It rev to the red line and still not upshift. I also tried the manual shift mode and auto mode but in neither mode the paddle shifter doesn't work. And no warning light or sound in my car at that time. Finally my car was towed to dealer. Second day dealer examined my car but they said everything was functioning. I picked up my car from dealer yesterday and everything was back to normal.

I'm really worried about this because unable to shift gear was dangerous especially I was on a high way. Since the dealer said there was nothing wrong neither the hardware nor the software. I suspect it may related to the cold weather, I live in new england area in US, it was 17F (-8C) temperature that day, and before that I parked my car for 3 weeks, during those 3 weeks the weather was below the freezing point at first with heavy snow but later it became worm one day with heavy rain and all those snow melt down. And the day the issue happen was freezing again...

I'm not super familiar with mechanical but I suspect it may cause by those reasons:

1. Hydraulic oil freeze

2. Snowed melted and the water licked into my car and freeze again. It may freeze the mechanical or cause short circuit on electric board.

3. Hidden car design flaw

I also suspected about broken pipe due to the bad weather but I tend to believe the dealer there is no mechanical issue. I'd like to write those down to let you know my experience, if anyone had the same problem please share your experience. I'm not a native English speaker, please ignore my bad wording if there is any.