I wanted to sort of close-the-loop with everybody here and lay out what is going on with these hubs and the solution we have.
What we are seeing is a small percentage of older V2 hubs failing to update the Zigbee NCP FW if the NCP FW is on v2.1.6. Luckily, there is a simple fix that has so far been able to recover everyone’s hub that has shown this issue.
If you find yourself facing this issue you can follow the factory reset steps on the below page for your V2 hub but you will want to make sure that you release the button as soon as you see the yellow LED STARTING to blink. You do NOT want to wait for the yellow LED to go solid!
The 25.x release will contain a fix for this issue when that ends up being released so this work around should only be a temporary solution 