How to pair a VA-HR

The manual says:

"Go to Settings>bluetooth to manually enter pairing mode."

On the watch, Settings>Bluetooth responds "Searching for Garmin Connect Mobile", not an option to manually enter pairing mode as mentioned in the guide..

But then there is no further progress: the watch remains in the Searching mode and goes no further.

GCM is up and running on the iPhone with bluetooth enabled (tested by disabling BT and getting the warning). No other BT devices in the area.

VA-HR running 3.30

iPhone 5 running "latest compatible version" of GCM 4.19.1.1 and reinstalled this morning.

Both devices freshly re-booted.

I haven't had to do this for a year, and decided to explore the "Restore Defaults"  option in order to assist a user with an otherwise unfixable app issue.

Is something broken, or am I just missing something obvious?