When I have a device connected to the 5 ghz band its works fine and I get 130mbps on speed test. However, on the 2.4ghz band I get max of 50mbps and this always changes to sometimes the connection being so slow nothing loads. I even tried putting my phone 1 foot away from the router and nothing changes. I need the 2.4 ghz band since most devices in my house don't supports 5ghz. Whats the problem?