One more thing to try on your side. On the Port Statistics page on the Netgear Management page, System > Monitoring > Port Statistics, check if there are any CRC error packets reported; may indicate...

Update: I tried again connecting all of the Deco nodes directly to the Netgear switch and the ethernet backhaul is now working as expected. I can even see in the Netgear Port Status screeen that the...

@dbonds I also purchased the XE5300 3 pack and I have a similar network config with a Goole Fiber Jack > Ubiquiti EdgeMax Router > Netgear JGS516PE > XE5300 Main (AP Mode). I could not get the nodes...