our x55's are not working very well in the garden room.  plan attached , room is number 1 main deco x55 is attached to the router at A  two other deco are at x and 2 M4R's are at "o" Deco units are not in cupboards and are table height.  The room is aluminium l which i assume is not helping .  All deco show good strength apart from garden room which is normally weak  it has shown good strength once or twice for short periods.

The house has recently been rewired so should all be on the same main, however i have bought two powerlines which fail to pair for any period of time.

If i can get them to pair do i plug the first powerline into the main deco via an internet cable and then repeat the process in the garden room or will this cause conflicts?

Is there anything else i can do to improve the situation or should i return them to the supplier and try a different brand?    I know seem unable to upload a pdf of the house plan is their a problem using google chrome?