I had the same issue about 3 weeks ago.
In addition to not coming out of first gear the display stated:
1. Service Electronic Stability Control
2. Service Trailer Brake System
3. Park Sense Rear Braking Assist Off
4. Service light was on (traction control)
I went out an hour or so later and the situation resolved itself.
In addition this past Sunday the speedometer, tachometer and Park, Reverse, Neutral and Drive switch were going up and down with the vehicle off. The vehicle would not start and the "situation" continued until I pulled the negative battery cable. I'm not sure of the battery voltage but I checked after using a battery tender a bit and it was at 12.2. Eventually the battery was charged enough to start the car and I took it out for about a 20 mile ride and all functions returned a little at a time. I only had hi and lo for heat initially and no back up camera. This happened Sunday and Tuesday morning it was at the dealership for an appointment with the 1st gear issue.
I do not have the vehicle back yet but I believe the battery was replaced and some things updated. It still at the dealer for additional updates.
My advice is to check your battery. This was discussed earlier today about batteries going out at the 2 year mark. I was told by a mechanic to replace the battery at 3 years (for new cars generally) and a lot of the problems he sees is do to the battery. My neighbor is a BMW mechanic and he said you can have problems when voltage goes to about 12 or a little less.
FYI
https://5thgenrams.com/community/threads/truck-suddenly-wont-even-try-to-start.26334/
I also believe this issue of being stuck in first gear is on car complaints
The 2019 Ram 1500 has 6 problems reported for will not shift out of first gear. Average failure mileage is 17,650 miles.
www.carcomplaints.com
Another issue to be careful of.
I just bought a 2019 Ram 1500 Laramie. I love the truck but twice now I’ve noticed it getting stuck in first gear and want shift into 2nd. I stop the truck shift it to park and then back to drive. It seems to reset it or something and drives okay ....Is it something maybe I need to adjust or not...
5thgenrams.com