This has worked for me on OBD2 and up Rams:

Turn the key on, no-start postion. Slowly push the throttle to wide-open and slowly release back to zero. Do it three times. Shut the key off.

Wait a second or two and fire it back up. Drive.

This procedure resets the Throttle position sensor.

I know yours is drive-by-wire, but this is worth a shot and costs you nothing to try.

If it doesn't work, disconnect the battery as mentioned for 20 minutes. Hook back up and it will go into "re-learn".

Trip to the dealer would be next.......