I've seen these be a bit flaky during pairing.
There's a timing issue where they seem to go deaf to incoming commands for 10 - 15 seconds which impacts any configuration being sent / received.
I've paired about 40 of these now over the past year, it's not a repeatable problem as far as I've tried, but it happened a couple of times during the first 10 or so that I paired, so after that I made a point to hit configure after a couple of minutes just to make sure.