To update this thread, I received the D500 back from Nikon very quickly.
The return label provided got the camera to Nikon in one day and I waited only a few days for the camera to be shipped back. Awesome. I had to settle with my D3400 for a bit.
The issue has not been repeated since I received the D500 back. They upgraded the firmware, did a cleaning, adjusted AF (not sure why), and replaced something in the camera. I don't have the bill with me at the moment.
Short version, Nikon took care of the issue and I couldn't be happier. Love the D500.