Since today we get the error below when do a git pull, push, commit (etc):
ssh_exchange_identification: Connection closed by remote host
fatal: The remote end hung up unexpectedly

We use ssh://git@altssh.bitbucket.org:443/<accountname>/<reponame>/

We have tried the following:

• created new keys
• eval ssh-agent && ssh-add <key>.pub
• restarted the machine
• from any other machine we don't have the issue.
• via https it works fine