I have upgraded the wiring for my local network to CAT5e and am getting much slower speeds from my Deco x55 network when connecting everything via wired back-haul than when I disconnect the x55 satell

Is there a way I can create a SSID / access point for a single unit of Deco? So for example, I have these Decos, DecoMain, Deco2, Deco3, and they are all in the same network as Mesh technology. But I