@alby1976 You have to find the router and RE sweetspots. Try AX73 wireless transmit power on middle and RE on intermediate or low coverage. You can use RE650 LAN port to connect wired device when in...

@TPint I really can't say what you should do - it is your ISP who should know what you have to configure. VR1200v has all means to configure a second internet connection with the parameters described...

@TPint Except the 2x FXS additional ports on the back (for voice) and the up-to-date FW (for VR1200v), the directions I posted are still valid.

@TPint You can get the latest firmware for your device from here. Update to Archer_VR1200_v1_1.0.0 0.8.0 v600e.0 Build 220711 Rel.67869n version and check again. From FW release notes it's compatible...

@TPint Try this guide and check if it helps in your case.

@alby1976 You can try lowering the RE650 coverage as well: