Devices connect to satellite rather than router which is closer

Just installed an Orbi 853 and I am having some strange behavior.  I have one device in my office about 6 feet away from the 850 router, yet it is connecting to a satellite one floor away and the signal is travelling through two stucco walls to get there.  I have another device in my bedroom and it is on the wall to the right of my office where the router is but is connecting to that same upstairs satellite which is both across the wall to the left of the router and through at least one stucco wall.  Why is this happening and how can I force devices to connect to what should be the best signal.