Just had Tachus Fiber (1GB) installed (previously had Xfinity 1GB). X20 shows 924 up and down coming into the router, however, even standing right next to the Deco via WiFi my speeds range from about 100Mbps all the way down to 10Mbps. No speed and no consistency. Trying to get WiFi off of my two other satellite Decos is obviously even worse. I'm not totally inexperienced at this stuff, but I'm at a loss. Spent a lot of money on these things and hoping there is some way to get them to work. Surely I should be able to get at least 250-350 Mbps while standing next to the router. I could get that from my Xfinity and netgear router a couple of rooms away. Problem was, I could get it upstairs so I was encouraged to try this mesh set-up. So far, not impressed. 

Any help would be appreciated. And please skip the stuff about distance to the router, placement, etc. Been down all those roads.

Thanks.