Feedback on Installing and Upgrading — Upgrade Troubleshooting
Feedback: Please include the hint to install and run "screen" when an upgrade is being executed over SSH.
1) Backup. 2) Open console (option 8), "pkg install screen", "exit", open console (option 8) again and next run the "screen" command. Next open console (option 8) again and run the upgrade process.
This did help me to upgrade a firewall via SSH without having to worry about the stuttering internet connection.