Okay, here's how I would proceed. The other codes you pulled may be legacy ones (not active in other words, the algorithm stores them for a while and unless the trigger is correct the light doesn't come on) but the salient one is the P0720.

Crawl under and on the front right of the transmission you'll see the harness connector. You may have to remove a bolt from a heat shield on some models.

Take a drip/drain pan with you when you go under.

The harness connector slides into the pilot bushing. On the pilot bushing you'll see a ribbed ring, turn that (can't recall the direction one way or another) and it will unlock the harness connector.

Pull the connector straight out. If you're greeted with a big belch of fluid, we probably have found the issue. Let it drip out into the pan (it will drip both from the pilot bushing as well as the harness connector), then plug the connector back in (remember it goes in and comes out straight, don't twist it!!).

Now go to the TCM (E-TCU), the transmission control module. It's in the electrical box under the hood. Unplug the connector and check the plug socket (this is the other end of that harness connector you unplugged below). If it's wet with ATF, then snap the plastic cover off the TCM and bath both as well as the socket with some aerosol electronic parts cleaner spray (non-residue type). Let them dry thoroughly.

Your truck will be parked for a bit, too. You'll need to source a new pilot bushing (part has been redesigned several times for just this reason, it leaks fluid into the harness where it fouls the TCM) from the dealer network, you don't want an aftermarket part here. Get a liter of ATF as well and you'll need the dipstick tool to set the level when you're finished.

When you have the new part, unplug the harness connector again, then unscrew the tiny screw in the center bottom of the pilot bushing. Pull STRAIGHT OUT on the pilot bushing to remove it. Lube the O-rings on the new one with some clean ATF, then align it properly and push it STRAIGHT in. This will take some effort and you have to resist the urge to turn it or you'll damage the conductor plate.

Once the new pilot bushing is fully seated, snug up the little screw in the center. It's only like 8nm or something, I use a nut driver and just go a bit past snug. Don't crank on it or you'll break it or strip it.

Align and slide in the harness connector, then turn the ring to lock it in place. Replace the heat shield if it was removed.

Head to the top and remove the cover for the AT fill tube. Start the truck and let it idle, insert the dipstick tool and read/set the level for the 25C range. The goal here is to have it as close to the minimum line for the 25C range.

Drive the truck a bit and then let it idle until the electric cooling fans cycle off, then check the fluid level on the 80C range. Target the middle of the range since the fluid may be a little cooler or warmer than 80C.

Remove the dipstick tool and replace the cover, you can fit a new locking tab if you like.

Take the truck to the shop and have the codes cleared, garden-variety OBD-II scanners won't clear the code from the TCU (that's the P07xx series) and until that happens, you're going to continue to have issues even though you fixed the underlying problem.

Good luck.