@jamesjamesa Your picture has rooms with their numbers, your Deco screenshot shows Deco names. If you can update your picture with names of Deco units and their placements, I may be able to recommend...

@p0rkskratchin It is likely there is something else that limits wired and wireless speed of devices connected to Satellite Deco, not the Ethernet port. To remove any possibility of Deco configuration...

@lainelaz I have similar setup and everything works just fine with Deco in Access Point mode. It is possible your ISP router does not support Deco backhaul protocol. Run the following test. Bring all...

@sastek You can't do that on Deco side, because Deco will prefer Ethernet backhaul to WiFi backhaul and there is no configuration option to override that. You may be able to do that on powerline...

@HatsieFlatsie The first thing to suspect is Ethernet cable(s) and/or networking switch. When issue happens, if speed drops on both Satellite Decos the suspects should be the switch, cable between...

@Al_Berko With the above network layout, as far as Main Deco concerned the network 10.0.0.x/24 is part of the Internet. You would want devices connected to Deco Guest Network be able to access...