Sunder My Enemies + Elemental Weaknes Curse (inserted in Blasemy Spirit gem)

Dear GGG,

I have been trying different builds for my Invoker and it seems like I discovered a bug. Whenever I use Sunder My Enemies + Elemental Weaknes Curse (inserted in Blasemy Spirit gem) together, damage against bosses goes down at least by 90%. I was expecting with non-critical hits, Sunder My Enemies would have no effect in terms of ignoring resistances. However, because of some reason, it affects the damage negatively.

I tried using only one of them at a time and didnt encounter with any damage issue. But together, there is something wrong.

I hope someone can take a look at this to make sure.

Anyone having the same problem, or not having it, comments are highly appriciated.

Thanks in advance!