I had the same problem, finally resolved with a Dexter adapter - apparently the truck has problems with not registering some LEDs and won’t power a light it doesn’t sense (not enough resistance)
Bump
I have a 2020 2500HD AT4 and I'm looking for the part# for the trailer TPMS sensors - can anyone help? My dealer's response to inquiry did not inspire confidence...
Also, going thru this thread, I get the impression my truck should have come with these sensors?