@MikeSel 

 

The options, other than beta software that might or might not work, would be to try repositioning Decos to get better results. That can be done in two different ways: to improve signal between Loft M5 and Living Room M9, or in opposite direction: to make it so weak that Loft M5 will abandon Living room M9 and connect to Master Bedroom M9 instead.

 

By the way, can you share signal quality between Loft M5 and Living Room M9? You can copy it from Deco app, this is what I am looking for:

 

 

 

Another option to consider is to replace M5 in the loft by M9. You can "borrow" M9 from Master Bedroom and bring it to the Loft where M5 is, turn off M5 and turn on M9 in its place. M9 has stronger WiFi signal, so it might do better than M5 and deliver at least 100Mbps.

If it does, you can bring M5 to Master Bedroom. That could drop speeds in master to probably 200-250Mbps from your current 500Mbps, but that should be acceptable if it can solve your loft WiFi problem.

 

If you want recommendations on placement of Deco nodes, you'll need to share their locations in your house. From your description, I think I figured on which floor which Decos are, but I can't figure where on each floor they are - and it matters. Below is simple drawing of house layout with Decos per floor as I read it from your description. Just download that image, edit with something simple like MS Paint to place Decos where they really are, and post it here. 

 

Also, it would help to mark places where you can move M5 in the loft. It should be where electric outlets are - and that would help with recommendations for better location of that M5.

 

Finally: is there TV cable terminating in the loft? That space must have electrical wiring, so someone might have wired TV cable there, as well. If yes, that could give an option better than powerline adapters.

Thanks @Alexandre, I understand what you're saying - but ideally I would like (along with many other customers) the ability to set the signal source. @TP-Link has mentioned on a couple of other threads that a beta update is available to fulfil this very requirement. I've tried swapping the units around and moving them further away from each other, but this isn't exactly practical in some of the areas of the house. (Due to no power sockets etc) The loft is still, persistently connecting to the living room deco, despite it being as far as way as it can be, and as close the the master bedroom as possible. I've also tried the trick of disconnecting the primary and powering on the loft, however, it still seems to revert to the living room.

Here is the signal status of the loft, the master bedroom M9 is using ethernet backhaul, so obviously a much stonger signal.