switching requirements for ethernet backhaul

What FW is currently loaded?
What is the Mfr and model# of the ISP modem the NG router is connected too?
What is the Mfr and model# of the ethernet switch if one is in the configuration. Non managed switches are preferred and with out any GREEN ethernet features. If you have a Managed swtich, disable all IGMP protocols on these switches.

https://community.netgear.com/t5/Orbi/Orbi-MR-2-1-Update-3-23-18/m-p/1553749/highlight/true#M30673
https://community.netgear.com/t5/Orbi/Using-Router-Configured-as-Access-Point-Cannot-see-Satellites-in/m-p/1612052/highlight/true#M37974
https://community.netgear.com/t5/Orbi/Orbi-Ethernet-Backhaul-with-Managed-Switches/m-p/1613897#M38123

Try disabling the following and see:
MIMO, Daisy Chain, Fast Roaming, IPv6 and Set 20/40Mhz Coexistence to 40Mhz only. Save settings and reboot the router and satellite(s).
If you updated to recent FW v.210, try enabling Daisy Chain. Some have mentioned that this seems to be working in reverse order, enabling means disabled actually.  So try this out as well.
https://community.netgear.com/t5/Orbi/Firmware-2-2-1-210-and-connection-problems-Skybell/m-p/1649275/highlight/true#M43001