I don't want to discount the disconnecting of the trailer could still have had something to do with this.
It seemed to go away for a bit, did you happen to notice anything trigger the last event? What were you or the truck doing?
So you could look at the rambodybuiler site and check a few wiring diagrams start from the trailer connector and see which computer is the closest to that it could be some random body control module took a spike when you unplugged your trailer, or the trailer harness its self.
If you were messing with a trailer again I would unplug the trailer harness for a bit and run it isolated a bit while you just cruise around, could have a bad wire or pins are smashed up.
Industrial CanBus needs to be terminated at at certain resistance, IDK what automotive is, but we use 120ohm as a baseline for parallel gen set controllers and multiple relays that are on the "bus", and depending on the distance a few times we needed to actually go to 75ohms what a mess of small resistors I had from radio shack to figure that out in the middle of nowhereville, usa... something is crashing your bus, so it seems they are trying to find something that is "bus" related so they think its the cluster,,, maybe because its lighting up and the sort,,, going crazy, obviously that appears to be a symptom not a cause after two of those are now on the pile. If you use that logic you would have to replace the wipers next and the locks you can see how quickly these symptoms add up.....or maybe the scan data was pointing that way or their troubleshooting tree they have a lot more info then us.
My overall point is something appears to be crashing the bus, or a module is bad,,,, troubleshooting wise, while it is in that failed mode you could attempt to try to get on the "bus" and check all the modules present. And see who is not talking back. Look at that module and related harness.
We had a '18 Ram 1500 maybe 45mile on the clock do the same exact thing you described, it had a shorted clock spring harness, if I still have the ticket will look. I was very surprised by that diagonistic report and have not heard of a clock spring issue or noted that way in a long time for a new vehicle. It was noted it was the harness not the actual clock spring issue of old, had a short in the harness that was taking down the bus.
If this is trailer related I would see if there is maybe a diode in that harness that makes it a charging only port, so backfeeding into the truck is prevented, IDK if that even exists this way doubt it, but to prevent a trailer from taking out the truck might be maybe a diode is shot and you are getting a spike when you unhook the trailer. The trailer harness or connector could be damaged.
We also had a '17 Promaster City that twice the OBDII port got smashed by drivers thinking the GPS was the parking brake, that causes a short between pins and also causes the above, by the way the parking brake is in the center console, no clue why they were lifting there leg so high to push the GPS plugged into the OBDII.
If you run any external gadgets on the OBDIi port remove them.
Only other thing if you do find a conclusion please post the end result.
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