LAGG interfaces lose MAC address
LAGG interfaces lose their MAC address, normally inherited from the first member, if all links are disconnected and then reconnected. The switch they are connected to is powercycled for example.
Create a lagg interface with two memebers. Set it to LACP. Check the MAC of lagg0 it will be 00:00:00:00:00:00.
Reboot the firewall it will come back up with the correctly inherited MAC.
Pull the links to the two members NICs. The MAC will remain correct. Reconnect one or both members and the MAC will revert to 00:00:00:00:00:00
Additonally editing an existing lagg anf changing its type, for example, will result in a void MAC.
This does not happen in 2.3.4