@Cardifftomo With your setup I would recommend Deco M9 Plus. It looks similar to M5, but slightly larger. It provides better WiFi signal. I know that for a fact as I run mix of M5 and M9 Plus in my...

@DaveP67 If you have Ethernet cable connected to your home network, there is a simple solution. Buy single Deco unit, such as Deco M5, connect it to Ethernet cable in your extension. That Deco unit...

@madebyDBM These documents could help with terminology, putting everyone on the same page. They also provide general understanding of technology and its limitations. If you are considering TP-Link...

@Ant72 If you bought Deco just to improve WiFi coverage, and otherwise happy with how your ISP router manages your home network, I would recommend to use Access Point mode of Deco mesh. In that Deco...

@Kogsbogs Read this TP-Link article first: General questions about Ethernet Backhaul feature on your Deco Ethernet backhaul should substantially improve Satellite Deco X20 performance. Even if you...

@KingZeus This Deco model has two ports: one is gigabit and another 2.5gb. If you have not tried it yet, connect Main Deco gigabit port to Arris modem and see if it makes a difference.