Bosses with Infinite Wards

So I've been playing a mage for my first playthrough and been loving it. However, I've come across this recurring issue, and I'm not sure if it's a bug or an intentional gameplay decision that I just so happen to despise. Several of the bosses, specifically magic focused ones like dragon priests, seem to have the ability to maintain a ward spell indefinitely, making them impervious to pretty much all direct magic. I've tried staggering them, tried draining their magicka with the mace of molag bal, and it never seems to work. I'm wondering if anyone else has had this issue. Is there an item/spell in game that can disable the use of wards? Maybe an AI mod that i can adjust to make bosses use them less frequently?