I know this has been asked a lot of times.

In my case it only stopped working now, as it was working fine just a moment ago.

I've tried switching to 443 port which gives me the error

ssh_exchange_identification: Connection closed by remote host

I'm accessing through cloud9. Locally it works. Github works both locally and on cloud9.

Also just before it stopped working, I may have made a lot of pull requests instantaneously, could it be that my (cloud9) IP was added to a reject list?