I have bought a Deco X60 3-piece kit. This is the setup

- I have a 300 Mbps cable service

- Main Deco unit as router, it is in the basement connected to cable modem (which is in bridge mode); main deco unit connected to a Netgear switch, as I have ethernet cable throughout the house

- 1st slave unit has ethernet backhaul, works perfectly

- 2nd slave unit has a wireless backhaul as I do not have ethernet cable in that room; I have 2 bars as signal strength, not 3 bars

The 2nd slave unit shows lower performance vs. the 1st slave unit connected via ethernet to the main unit.

Can I use powerline as backhaul of the 2nd unit instead of wireless, and would that be better?