Thanks, @dman2306 & @SoundersDude.
Yeah, the token is a very simple copy/paste, and I've done it for every other Ring device I have, and I've re-re-re-verified no spaces anywhere. 
Regarding what I'm tracking, it's motion, not a ring. I have the Ring Video Doorbell 2 listed once in my motion payload section:
Body Payloads for Motion Events
Ring Spotlight Cam Wired - Side Gate:
- { "kind": "motion", "motion": true, "id": "RING-xxxxx" }
Ring Floodlight Cam - Driveway :
- { "kind": "motion", "motion": true, "id": "RING-xxxxx" }
Ring Video Doorbell 2 - Front Door:
- { "kind": "motion", "motion": true, "id": "RING-xxxxx" }
Ring Floodlight Cam - Backyard:
- { "kind": "motion", "motion": true, "id": "RING-xxxxx" }
Ring Floodlight Cam - Shed:
- { "kind": "motion", "motion": true, "id": "RING-xxxxx" }
And once in my "ring" payload section:
Body Payloads for Ring Events
Ring Video Doorbell 2 - Front Door:
- { "kind": "ding", "motion": false, "id": "RING-xxxxx" }
I'm only been using the motion payloads. (In fact, I didn't even notice the "ding" payload until just now.) 
So I'm still mystified why the doorbell won't cooperate.
