If you run WordPress maintenance for clients on Xserver, sooner or later you hit this: SSH was working fine this morning, and now your connection dies the instant it touches the host. No key change on your side, no obvious server-side incident. Just Connection closed by ..., and the silence deepens every time you retry.
A recent escalation to Xserver support gave us an official answer about what's actually going on. Worth writing down what an operator needs to know.
What the symptom looks like
In our observation, the symptom moves through two stages.
Lighter: Connection closed by [Xserver IP] — connection killed at the sshd layer before it's established
