XF 1.4 Site not working on phone (3G/4G/LTE) Error 502

[AppleGuyPro]

So my site seems to not work when attempted to be viewed on a phone with a data network. It works just fine with Wifi but does nothing and only gives an error of: "502 Bad Gateway - Response Error, a bad response was received from another proxy server or the destination origin server."

Im pretty sure this is a host problem, but can I just get a confirmation?

 

[AppleGuyPro]

I just learned this is most likely my carrier's (AT&T) problem. Anyone have more info?