Had this happen on my wifes 2021 Limited w/etorque. Happened twice before I found a "remedy" to the problem. Both times it was cold outside, my wife was driving, she stopped at the stop sign, the truck shut off to save fuel, she takes off from the stop sign, truck turns back on we start rolling and get to 15mph and then all the sudden truck lunged forward, shut off, the gear selector knob flipped itself into park, truck applied parking brake - if it had just been me driving solo it wouldnt be a huge deal but my 4 year old was in the truck both times.
Called dealership, they said without a warning light they will need the truck for at least 2 weeks just to diagnose it and since it was an intermittent problem the chances are they wouldn't be able to replicate it within the short distance they drive it for troubleshooting. Mind you they just had the truck for 4 weeks to replace the cracked manifold and do a front and rear differential service only for us to have a new grinding sensation in the steering wheel when turning left/right at certain angles. This wasnt a problem when I gave them the truck so someone fked it up servicing it so my confidence they would be able to fix this new shutdown problem was LOW.
I remedied this complex problem by trading in the SOB the first week of march and walked away from the problem and likely RAM/Stenallis for a long... long time. I'm too old to deal with ******** from cheap *** dealerships that cant be bothered to carry loaner vehicles anymore despite selling 100k trucks
. Went to Sewell and bought a Subaru Outback which is what my wife wanted since she drives 3,000 miles a month (real estate) and 26mpg is much better than 14mpg. I'll probably buy a 2020+ GMC from Sewell and just suck it up that it lacks many of the features the ram had. Until the issues arose, I loved both our RAM trucks 2019 and 2021 never had the leaky rear window or common issues others seemed to have, but ill be damned if I put my kid in an unsafe/unpredictable vehicle.
Best of luck to you all out there and hope RAM does the right thing.