I think that the plugin is only checking if the offline player is the leader, and I would like to know if its possible to be done that it checks all the members of the team, because it can be that the leader is offline but there are players connected.
Only checking the leader of the team
Anti Offline Raid determines who owns a structure based on who built it.
make sure that you set in Anti Offline Raid
"clanFirstOffline": false,
"clanShare": true,
"minMembers": 1,
require players to create a clan. I use, rustio-clans
and set the following setting in rustio-clans
addClanMatesAsFriends": true
this should work