Superhub : Large files not downloading, but internet is fine - help?

[poweroverwhelmin]

For the past month I've had trouble downloading large files over my 60mb/s connection. The downloads work perfectly for a few seconds then abruptly stop, and the download speed goes down to 0B/s, at the same exact place. This has happened with every download I've tried, on around 4 separate computers (2 windows 8, 1 windows 7 and one OSX Mavericks).

The confusing thing is that while all this goes on I can still load webpages perfectly, and also stream videos. Furthermore when I use a download manager like DAP I find that when many connections are made all the connections download to completion except the first connection, which once again abruptly stops at the exact same place every time.

I have a superhub 2 as a router and have disabled the firewall, I've have uninstalled avast antivirus and am using malwarebytes. Any help would be amazing.