@Sunshine thanks for your reply the problem is that looks not compatible with Ethernetbackhaul and then I don't have the same ssid how can I solve this? Only with another archer c80 or with a deco?

this should happen!

I've an archer C80 as main router on my living room, I've connected two ethernets to it that go to 2 other bedrooms, and I've bought a RE700X to try to use as Acess Point and extend the easy mesh...