WN30000RPv2 Wifi Range Extender Setup nears completion, but won't connect other devices

I'm trying to connect a WN3000RPv2 to my existing Orbi Mesh network.

I've used this same WN3000RPv2 on my old home internet system at a different house.

I have the WN3000RPv2 next to an Orbi satellite. It has a strong connection. I followed the setup instructions, successfully made it to the screen that tells me to go connect other devices (after it's renamed the extender "myhomeinternetname_ext," but then none of my other devices connect, and it says can't connect.

I've factory reset the device and retried this two dozen times. I've also restarted my Orbi system.

Any advice?

Thanks in advance.