Do you do convoy? In 4.0 you get a total of 3 chance including convoy and plunder. if you finish 3 convoys then you cant plunder more. If thats not the case, is it that you cant see anyone might be because of level gap(its 15 i think). Did you ask your server mates? Can they plunder? Or is it when a SS runs, and you come to base and you cant see them?