HA Failover Behavior - With and Without monitored Ports

https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/HighAvailablityStartupGuide/HAConfiguration/HARuntimeConfiguration/index.html#monitoring-ports

Please describe the intended HA behavior (active-passive) if there are no monitored Ports configured. Does the HA failover only happen if the Primary Device fails or is not reachable via HA Link?

There is some discussion at the Community, but the Documentation should include this crucial Information: https://community.sophos.com/sophos-xg-firewall/f/discussions/100131/active-passive-with-no-port-monitoring