|Make and actual models of both routers would be most helpful here; presuming that the "gateway" is of course also a router?|
Does the office "gateway/router" have wifi capability?
Also - why the need to connect to the office gateway via wifi; when you have a cat-6 cct. already established. A hard wire (cat-6 in your case) is by far the more stable and faster; and also more secure?
Remember too that distance, and also the nature of any "objects'/structures etc.", between the source (gateway) and your house is a factor in stable/reliable wifi connections...