Knockback damage on the Half-dragon isn't working properly. The correct damage, the predicted damage, and the actual damage are all different numbers:
I had 25 base damage (33 after bonuses) and 120% knockback damage. I was going to knock the monster back into another monster.
The correct damage is 48 (33 + (25 * 1.2 * 0.5) = 48)
The predicted damage was 64 (33 + (25 * 1.2 * 1.0) = 63)
The actual damage was 41 (???)
It's worth noting that I was using the Strength Potion. So it's possible that the fix for the Reflex potion broke temporary buffs working with on-attack knockback effects (e.g. Bear Mace, Half-Dragon, etc)