I have FTTP with a master M9+ as the router (not the ISP's provided router). This connects to a TPLink unmanaged 24-port switch. I have a number of satelllite M9+ in access point mode, connected by ethernet backhaul to the switch.

I bought a pair of OREI hdmi to ethernet encoder/decoder. Before I did so, I asked OREI ifthey work over a switch / ethernet set up. They said it would. Well, it didn't! (but did work when tested with a dedicated ethernet cable). I read someonewhere (but as a novie, I didn't really understand it) that I could set up a eparate network using he Deco app on my smartphone.

When I tried to do this, after selecting "Create New Network" it says to plug in Deco and wait for blue light to pulse. To me, this seems like it thinks I'm adding another Deco but I don't want to do that. I'm out of my depth so am wondering where I've gone wrong. It's possible that I need to dedicate a Deco M9+ to the decoding end/device? (and that's before I get into all the port aloocation and taggingstuff (which I don't really understand either!).

I think I need an idiot's guide! TIA.