Ryan - found the fix with my provider, looks like its the same with Xfinity.
Follow
this link to access your Wifis admin. On the left side you should see firewall.
To get it working, I had to change both the IPv4 and IPv6 settings from "Typical Security" to "Custom Security". Click on "Typical Security" and make sure "Disable Entire Firewall is checked off.
Once you save your settings, it should hopefully work!