I think it has to do with your internet connection also. Ours was not the best and had to have the company come. They always say the same thing, "You have too many connects." We always say, "We've had these for years." Then they say it's their fault and needs more equipment "on the street." But when they get around to that, who knows. We ended up paying extra for a little more juice which we should have anyway.
I'd start with your cable company. My husband may have more suggestions when he gets home; he's the electronics genius at our house! Good luck. P.S. Don't let the cable company tell you that it's "your fault" or "you have too many outlets" or anything else. You should have enough juice to work your equipment. They are like doctors; they are god and you're an idiot!