FWIW, I have the chip working properly now.
I pulled the wire install out, sucked out the solder, and used the pinheader instead. I've always used a wire install on the boxes that already have solder in the port (so much easier) but I remember the wire jack with this chip seemed kinda loose. i shoulda acted on my instincts.
Lesson learned -- I wouldn't have guessed most of the chip features would work if one of the pins was dead.