Zerphis heart buff removes soul gain prevention of vaal blade flurry

During my testing i found out that while having the soul eater buff from zerhpis heart vaal blade flurry had no soul gain prevention timer therefore i was able to spam vaal blade flurry as long as i was killing enough enemies to gain the souls required for the cost.

did you by chance have the "players vaal skills do not apply soul gain prevention" sextant affecting the zones you were testing in?

Tried it in both maps and in campaign zones. I didnt have the sextant.