I don't know if essence bug on beast.

Currently specced into Essence, Einhar, and Alva. Amplified energies for essence makes every essence a T6 and I am using an Essence scarab of Ascent which makes them all T7 (Deafening). Using Essence scarab of Calcification. All rare mobs in incursion have at least 1 Deafening essence on them. For some reason on beast they either have Deafening Essence or they don't. Some do not even have T6 essence. I also use Beastiary Scarab of the herd for 5 additional red beast. That may be the issue but I am unsure.

I'm running the same strat and my beast only have screaming or lower essences