@bobbyD, there are more than twenty similar cases linked to the Double Luck Voodoo workaround ...
Zigbee 3.0 devices will not pair via Zigbee 3.0 routers when the Zigbee 3.0 coordinator routing table becomes full (max 32 direct pairings or 32 pairing attempts, even if the total number of the directly paired Zigbee devices is less than 32.).
The C-8 'Rebuild Network' operation seemingly clears some routing tables and provides a time window for paring of the Zigbee 3.0 devices directly to the C-8 hub, It has been this way for many moons ...
