@Andy_Capp I think @David-TP will guide you in details.

@Andy_Capp Hmmmm

@Andy_Capp You can use Deco X50 (5G) as a Main Unit and then you can use Deco M9 units as Satellite Units.

@dooncomputer You can downgrade to previous firmware 1.2.11 by using Web UI manually.

@Jay_B You can do the factory reset to all Deco units manually by using reset button and then create new TP-LINK account and then do the setup on new TP-LINK account and then u will able to access...

@Jay_B You can change ip address on your Deco system and the whole deco system will automatically follow the changes.