With 2,800 miles the P to R / P to D neutral/clunking problem happened again 2x more times since my dealer appointment to resolve this problem a couple weeks ago.
So, I took it in to the dealer again yesterday for yet another appointment to try and resolve this problem. This was the THIRD time for this specific problem. Reason for yesterday's appointment is this problem occurred again last weekend; 5 days ago after driving 30 miles and parking for 2 hours.
At yesterday's appointment, the service writer and I agreed to not even leave my truck there, but they documented the problem; with the reason being they couldn't do anything since there are no related TSB's or software updates and the failure wasn't occurring at that time.
And then yesterday the problem occurred in my driveway after I got home from the appointment. This was after driving 6 miles and parking for 15 minutes. I immediately called the dealer while it was idling in D with e-brake light "off".
After ~5 minutes on phone discussing the problem and possible solutions with the service writer, I realized that the parking brake must be "on" when it's having the problem, because I was parked on an incline and even thought "BRAKE" light in cluster was not illuminated, the truck wasn't moving.
I cycled the e-brake off and on, but this did not affect the problem. I then slowly revved the motor and it clunked into gear and lurched forward when the tachometer reached 1,000 RPM.
We agreed that I will set up another appointment next week to have them look at the parking brake system to again try and resolve this problem.