I have a network running with a Dec x55 as router and 2 satellites hard-wired to another floor and a detached building. But I have gotten access to a Fortigate device and would like to switch over to

I have just had AT&T Fiber 1Gb installed. I connected my Deco x55. I have 1 base station and 2 satellites (hard cat6 backhaul on each). AT&T’s onboard speedtestfrom the fiber gateway shows 1.3Gb down