Weird thing. 2019 Cascadia. Been driving since day 1. Two days ago, during pretrip, the tractor taillights turned off.
I can shut down the truck to reset, and they'll go on. Then 2 minutes later they're off.
I have a light bar, and the turn, backup and brake lights all work fine still.
The trailer running lights also work when tractor lights have gone off due to this intermittent weird thing.