Can't Get Online Despite Xfinity Gateway Being Online and Connected

I've been trying to set up my Wifi at my new apartment. I've had two technicians come through, and one of them was able to successfully get my Xfinity Gateway hooked up and online. However, when I connect to my network and try to get online, it says that I am not connected to the internet and takes me to the below Xfinity Page:

http://connectivitycheck.gstatic.com/generate_204

The page says "Managing your home network settings is now easier than ever. To manage your gateway settings and other features, please download the Xfinity app." I already have the Xfinity App and everything looks correct in there, so I'm not sure what the issue is and why I can't get internet. Please help!!