Reboot the devices that won’t pair

Reboot your devices if the suggestions so far have not helped.

This may sound like the kind of bad advice you get at a technical support call center but in the case of the host computer device a reboot can be surprisingly effective, especially in the case of a desktop computer or smartphone, that reboot really can sometimes make a difference.

If a reboot of the host computer doesn't resolve things now try resetting the connecting Bluetooth device by forcing it to pair again.