Problems w/ New WiFi 6 Nighthawk 8AX - EAX80 Range Extender w/ New WiFi 6 Nighthawk AX12 - RAX200

Real similar set up to yours ( previously ran the nighthawk router, upraded to orbis, upgraded to Orbi AX wifi 6 and immediately returned due to the lack of custom configurations I was expecting to see, sprinkled in a few nighthawk pro gaming switches, later went with the RAX200 + EAX80 combo). I expected this would be the secret sauce / high power solution compared to the Orbi AX Wifi 6 but sadly the EAX80 constantly dropped out in weird ways where the lights would be looking OK, but the actual performance and stability would beg to differ. I was hoping for ethernet backhaul similar to the Orbi line but was pretty surprised when that didn't seem to be supported off the bat with the extender in default config.

BUT, have you tried AP mode? If you have hard wired Cat5/6/7 throughout the home or even coax cables + MOCA adapters you could probably run the extender in AP mode which does recognize the hard wired ethernet connectivity. I just switched my RAX200 + EAX80 combo over to this and it appears to be working pretty well for now.