You lie about your fiber speeds

I have a 1GB/s fiber and the heights speed teta I got was 479mb/s. The worst park is when I took the deal they gave me a router and max speed on it is 1350Mbps. Then I saw the 2.4GHz is 450Mbps and the 5GHz is 867Mbps. When I contacted them they said it's up to 1GB/s. I have never gotten to 1GB/s ever