@Thomas3857 You have to attach it to something, either straight to the router or through a switch/hub that is attached somehow to the router. If you have a wirless extender working with the router...

@SkiDownFast I am using this: RE655BE | BE11000 Tri-Band Wi-Fi 7 Range Extender | TP-Link with my BE800, have a seamless MESH through out the house. Simple to set up, just did it with the WPS button...

@markcarls Is WPA3-Personal+WPA-2PSK[AES] not an available option for you? Thats how I have my Archer BE800 set.

No email here, so not sure what to tell you. If the links look legit, give it a shot.

@SebAlvarez What is your DHCP address range configured at? The reservation must fall within the range.

@coffeeskier Depends on how you have it set up, if it is a MESH setup, then no everything will be the same. If you put it into access point mode then you shold be able to change the password.