if there's an option for turning off caching, or "network speed up" in your modem, turning it off helped for me when I was trapped with hughesnet for a while.

if there's an option for turning off caching, or "network speed up" in your modem, turning it off helped for me when I was trapped with hughesnet for a while. moved me up to about 75% of GitHub.com requests working. essentially, their caching mechanism was broken for a ton of the sites I went to visit.