Love trail 42. Used to run that trail all the time back in the late 90’s in my 66 bronco. It was an especially fun night run. Might have to make a special trip down from Moab to run it.
My 96 was doing the same thing. I removed the aftermarket car alarm that had many ties into the wiring harness including the neutral safety switch. That fixed my problem of the transmission not staying in 1st gear when descending and up shifting...