Sorrow of the Divine's "Zealot's Oath During Effect" being affected by flask effect

As stated in the title:

When activating Sorrow of the Divine with a "Nevalius Inheritance" unique belt equipped on my level 27 character, my character does not receive the effects of Zealot's Oath. I'm assuming the flask explicit is also affected by other reductions to flask effect, despite being tagged as an "Unscalable Value".