I have been able to connect a couple of times only and when close to the modem. When I'm upstairs I switch to the 5Ghz band. Although when it works you get very nice speeds as shown in the picture below.
Hopefully this will help you. I have exactly the same hardware you have and had the same issue. - Go with with your macbook close to your modem, i.e no interfering walls, etc- Set the SSID on the Gigahub to be the same across all frequency bands- Us...
