Unable to connect third Connect Home Hub model ET-WV520

I hope I am posting in the right section.

I purchased a three pack of Connect Home Smart Thing hubs, model number ET-WV520.

2 of the hubs set up no problem. The third, however, does not blink green/red as per the instructions, it only blinks green, then solid green, and does not allow me to connect.

I have tried using the reset switch on the device, but that didn’t help.

Please point me in the right direction.

Thank you.