I have the exact same issue. To my understanding this isn't triggered by any events or setups, as long as you have a companion with any looting skills in the party you will get absolutely no loot at all. Even just having them in your party greatly diminishes your loot as well. In 4.2 I've finished Varis's quests multiple times and summoned Danny, and never saw the bug about not being able to talk with her or her doing anything nothing but patrolling around, but I am suffering from this looting bug really bad.
