Today, the web site http://sila.altervista.org/ started timing out with Error 504 "Gateway Timeout" when trying to reach it via mobile data (4G) from my T-Mobile-branded Samsung Galaxy S III. The same site loads on the same device just fine via WiFi.
I found a number of similar complaints ("the phone can see the site over WiFi but not over T-Mobile's 3G network"):
Getting a 504 Gateway timeout on US T-Mobile when connecting to MemSource Cloud « MemSource Support Forums "This is a known problem with US T-mobile - they fail to route to certain web services";
"Error 504 Gateway Timeout" on phone? - Yahoo Answers "Don't worry you won't have to buy a new phone. It's a network problem with T-mobile. You'll have to wait until they fix the issue. I just spoke to a rep and she explained it to me that 3g and 4g phones are affected";
Re: Error 504 gateway timeout;
Re: HTTP 504 error for http://arizmendibakery.org .
T-Mobile, please help.