@jrm40982 ethernet backhaul should work with any satalite you are able to connect, even if other satalites are not using ethernet backhaul. The unwired satalite should then determine if the base or the other satalite is the best route for it's wireless bridge. I have the X50-PoEs and when I had a switch that interupted the backhaul from working on ethernet to one of my satalites it connected to the main over wifi since it was the closest node of the mesh. I've since resolved the switch issue at that remote satalite and all are on the ethernet backhaul now as I wanted for best performance. But as stated and I've expriences, mixed backhual modes (ethernet/wifi) work. 

In the App, you have confirmed on the network map the backhaul mode being used to both satalites? Is there any network work switch between that base and the second floor satalite?