Here is what I found out. Dealer had my truck for a week and I don't think they really learned or did anything. They talked with VOXX but so did I. I also called and spoke to a tech at VOXX and this is what needs to happen. I had already updated the firmware in the settings, (Fire OS 7.2.9.1 (PS7291/2964)), but the key here is that you have to remove power and let the system do a good hard re-boot. The VOXX tech said remove power and then apply the update, I did it in reverse and so far so good. He said that this 2964 update was the update to correct this power issue where they are not powering down.
Now, the dealer tech in their infinite wisdom, I do not believe ever took power off the system. There are 8 grommets that you use a interior trim tool to remove, in order to remove the top portion of your seatback (on our Lincoln seats anyways,) as that is where you get access (from the front) to the two connectors for the RSE. I asked the VOXX tech why don't I just disconnect the negative on the battery and remove power from the vehicle that way, instead. He said sure, you could do that, too. As long as you're certain you're getting 12v from the pin in the connector, of course. Let's face it, this is a known issue and I don't think Ford/Lincoln has anything miswired. So after screwing around with my truck for four days, they finally parked it back in the lot for the weekend. The dealer/VOXX had come to the conclusion that if the update didn't work, they needed to replace the RSE units.
My Left unit already needed to be replaced because the screen was scuffed in transit, so I will still need at least that one unit, regardless. However, when I found out Monday that VOXX had no units to ship and they didn't know when they would, I told the dealer that I'd like to pick up my truck ASAP and we can wait on the parts to come in. They said I could pick it up the next day which I did, only to find out that it had been dead as a doornail for days now. This dealer's lot is full and I cringed having to leave my new truck that we paid good money for, on their lot with the potential for a door ding.
We had to jump-start our new truck with just 400 miles on it, but we couldn't even get in the vehicle because they parked another Corsair too close to the driver's door. I had to drive my truck home with the windows down in the mid 90's, no a/c, cameras, or radio, because the battery didn't have enough charge. When I got home I put it on my Cetek charger but after that power loss, the update finally took and my RSE units correctly powered down when the vehicle was shut off. The next time however that I used the units, the one on the Left stayed on so I removed power again for about half an hour, reconnected the negative on the battery and it powered off with the vehicle again. I attempted to see if new updates were available and they were not, but it did give me a prompt to install the update so I did that and we'll see again what happens. I think it needed to finish installing the update and hopefully, it will power off with the vehicle the next time we use the Left RSE.
VOXX knows what is going on more than anyone at Ford/Lincoln.