@Michael47110815 There's no specific method for this to be tested - it either works or not. Here's how to configure WDS on your router - you may check your C7 if it's properly configured.

@Brad999999 Another approach would be to set AX6000 LAN IP address manually - 192.168.0.254 and its gateway 192.168.0.1. Check the LAN port status on your HB810 router, where the AX6000 is connected...

@Brad999999 Set updated AX6000's DHCP to OFF and test again. If your other AX6000 is in AP mode too, set its DHCP server to OFF too. The connection between HB810 and AX6000s should be HB810 LAN port...

@Drizit Your observation is correct - here are more details about the purpose of TP-Link's IoT.

@Brad999999 Put some screenshots of your AX6000 LAN and DHCP settings as well as its Network Map:

@Shoulders Here's the list of routers that support the Easymesh with an ethernet backhaul. BE450 doesn't' seem to be in this list, but the list is dynamically updated, so keep an eye on it.