I play with a gamepad and use a custom filter for targeting NPCs/Objects since in heavily congested areas it can be difficult to target quest targets or other "NPCs/Objects" but even with the "Minions" box unmarked they are still being targeted. I assume this is not really a bug per se but more because they are also considered NPCs. In my opinion, if they're going to have their own target filter they should only fit under that target filter and not also be considered an NPC. It would be nice if this could be looked into, addressed and/or fixed.