I have a mixed Deco mesh 3 x X55 and 1 x E4R.

One X55 is the main Deco in the Study with other X55 in the Lounge and the E4R in the Integral Garage.

There are ethernet  backhauls  from Study to Lounge and Study to Garage.

The Deco app on my phone shows that the garage Deco is connected by Ethernet but the Lounge shows a WiFi connection. However devices connected to the switch in the lounge all indicate an ethernet connection proving that the physical cabling is good.

Any suggestions as to why the backhaul is not being used.

Thanks