Thanks, everyone, for the suggestions.

After a different diagnostic strategy, I discovered I had made a really dumb mistake.

I accidentally swapped (from a working scrap of code a few days ago on a different sensor device) my ADCIN channels. In the code I originally attached,

ADCIN 2,FAR
ADCIN 1,NEAR

should have been

ADCIN 1,FAR
ADCIN 2,NEAR

My apologies to all, but still, THANKS!