My house is a dead zone for wireless

I am having a terrible time with a wifi signal in my house. I have fiber to my house at 100/10. I have a great router that boast led of being one of the best on the market. My house is long and the router is on the north end. The house is brick and doesn't have a metal roof. The signal completely dies less than 20 feet away. I have tried several different routers to only have the same issues. I have tried all types of boosters ect to no avail. Cell service is horrible as well. Does anyone have any suggestions on why this is happening or what I might try to fix it? Thanks