Steps to Fix:

1. Open VSCode.
2. Press Ctrl+Shift+P (or Cmd+Shift+P on Mac).
3. Type "Preferences: Open Settings UI" and select it.
4. Search for "Remote.SSH: Connect Timeout".
5. Change the value from 15 to 30 (or more if needed).
6. Restart VSCode and reconnect.

Why This Works:
By default, VSCode only waits 15 seconds for SSH to connect. If your server takes longer to respond (due to network latency, server load, etc.), it times out. Increasing the timeout gives SSH more time to establish the connection.