RESOLVED!!!
Well, it's been quite a journey over these last several months, but it appears that I finally have a working camera with the invisible trailer view. It turns out, the plug on the camera line that plugs into the bumper port was defective. Upon inspection, it appears that the plug was never properly crimped onto the coax cable.
My dealer gave me a new camera. It has taken me a few months to get around to installing it on my Airstream, and now that's done. The invisible camera view worked on the new camera without any calibration, but the camera had a bit of "fisheye" distortion and the boundaries didn't line up very well. Somewhere I read a recommendation from @MTU Alum to adjust one particular dimension and recalibrate. WOW, this is now better than ever.
In summary:
1. Original camera had defective plug, which resulted in lagging image or no image
2. Replaced with new camera (different part number, by the way) and it works as it should
3. Heading out this afternoon to enjoy the long weekend in the RV. Looking forward to having invisibility option to help negotiate traffic on the freeways this afternoon
Recommendation: If you're having image issues with the camera, have it exchanged under warranty. IIRC, you've got a 1-year warranty if purchased as a part, or 3 years if you purchased with your truck.
Enjoy!