What FW is currently loaded?
What is the Mfr and model# of the ethernet switch if one is in the configuration.
What is the size of your home? Sq Ft?
What is the distance between the router and satellite(s)? 30 feet is recommended in between them to begin with depending upon building materials.
What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and any unused channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?
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. Hoping NG support can have a look at this. So try this out as well.
https://community.netgear.com/t5/Orbi/Firmware-2-2-1-210-and-connection-problems-Skybell/m-p/1649275...
