Shellbust working strangely

I’ve been extensively using Shellbust thanks to finding an Imp Hexer early on, and as of patch 0.0.41 it’s now not behaving as expected. It’s doing an amount of damage equal to the defense lowered, insread of 200% the defense lowered; that or there’s a display issue on either the amount of defense lowered or the amount of damage being dealt. At first I thought it might be due to enemy artifacts or traits, but it’s been consistent across several realms worth of fights.