I have model M4R as a hub with other units in the house connected both by cable and wifi .  i'm trying to extend my mesh network to my cellar going over a power line adapter and then connecting a X50.   However, it does not seam to be connecting even with the main deco connected to an ethernet cable and power line adapter on the other end.  I was running the same power line to a TP-Link Router TL-WR902AC, which was working but I wanted to keep evething on the same mesh network to allow homekit and other apps to work together,