Well....problem fixed! For years, on every trailer we've ever had, the entry door had the hinges on the right and the lock on the left. In this config, the handle latch was the upper keyhole and the deadbolt was the lower keyhole. On this truck camper, the door is reversed, meaning that the hinges are on the left and the lock on the right. The means that the lock is installed with a reverse orientation, and you guessed it....the keyholes are reversed. I went out there in the dark and had the key in the wrong hole. Daylight fixed the issue!