@eplante Did you try the High Speed mode in RE605X Advanced setting - details.

@Sabhanam In order to be able to connect all your 4 PCs to each other, you have to configure one of the Archer C6 in AP mode (Case 1) so they can be in the same subnet.

@Wrigs79 Login your VR2800 WebGUI - details. Did you set the VR2800 in wireless router mode ? Post some screenshots of VR2800 Network Map menu and describe how did you connect your Telstra modem to...

Since AX90 is a Onemesh capable only router but AX72 is an Easymesh capable here's a post where the user succeeded doing this via WPS method.

@TPBINZA Well, it depends on what's your Internet connection type: These guides are using PPPoE internet connection type. If your ISP is using Dynamic IP then probably you should consult your ISP...

@kodein Keep an eye on this thread for any new RE model which supports Easyemesh via ethernet backhaul.