One thing to bear in mind is hen a range is stated with a wireless set up, the range may be based on a connection thrr into a ough fresh air, once you have a solid material barrier then the range will begin to reduce.
If the barrier has something which is conductive electricaly by some degree theen this will have an effect on the radio signal. In a typical dwelling this can be brick, concrete, gypsum (plaster). Also if there is a metalic barrier such as foil backed plaster board, foiled cavety insualtion, steel frame structures. Lime mortar is very conductive with the slightest bit of water content (from normal air humidity) and is notoriously problematic with radio signals. Also furniture such as a filing cabinet (I have been to a broadband fault where the connection to the router was ok but the router was on top of a filing cabinet, the end user was downstairs with a laptop, I moved the router on the desk next to the cabinet and "Hey I'm connected, what did you do ?". another fault where one side of a wall the router wouldn't connect to anythting the other side. plugged the router into another socket where from the route point of view the wall was almost edge on and every one could connect.
The yard at work where I park i can pick up the wireless signal in the van along one side of the car park over 50m radius, yet 10m away in the other direction in the building, nothing, as the signal wil have to get through 2 thermite walls and 4 lots of metal lockers.
Move the router around a bit, you can get booster aerials that plug in the back of a router to help as well