Orbi RBR750 support and Ethernet backhaul

I have an RBR750 plus 3 RBS750 satellites. I have had nothing but problems since purchasing almost a year ago. I have reached out to Netgear literally dozens of times—each time they take 2-3 hours to conduct lightweight troubleshooting, then promise to follow-up.  After I wait a week, nothing happens, and the process repeats.  Netgear service is pathetic. 

A couple weeks ago I learned that they think I never returned a device that was RMA’d.  That is completely untrue but nobody at this company will listen or be helpful so I’m stuck with expensive networking that rarely works and never works well. 

Perhaps this amazing community could help with my latest problem:  one of my satellites lost connection.  It doesn’t even show up as a disconnected satellite in the router app or web interface.  I’ve tried adding the satellite from scratch but no joy.

But here’s the thing—it’s connected via Ethernet.  I’ve confirmed the Ethernet is fine. There’s even a device (a Lutron hub) that is hardwired to the back of the “disconnected” satellite that functions fine and shows up in the router as a hardwired connected device.

How can a disconnected satellite provide connectivity to a client device?  And since Netgear won’t support their products, I’m wondering if anyone in this forum has any suggestions on how to connect this satellite via Ethernet?  TIA…