Hi everyone heres some background context

Internet Service Bell Canada 1.5gbps Plan

4000 SQ ft home

model Deco X50

Deco's are in wifi router mode

Modem in Basement connected to Main Deco Unit

Sattelite 1 is in kitchen 1 floor above

Sattelite 2 is in Top Floor Bedroom

My Deco that is in the top floor is connected by an ethernet cable. I am getting about 800-900 speeds when i connect an ethernet either into the port directly or into the deco x50 so speeds there are pretty consistent. However when i try to connect to the Deco on the top floor using wifi im getting very slow and low speeds raning anywhere from 10-40 mbps. I understand with greater distances wifi speed is slower but i was under the impression with a ethernert cable connected into the deco i should be getting really good speeds. 

Am i wrong on this or is there something else happening.