Incorrect damage to heroes

Just noticed, second game in a row, that if the opponent has the 5 armour from the tavern spell, it counts as 10 in the damage calculation.

The opponent had 11 health and 5 armour
I hit him for 10 dmg, and they was left with 11 health 0 armour…

The other game they had 3 health 5 armour
Hit them with 11 dmg and they were left on 2 health

Edit 1: It seems it calculates properly when the damage is fatal

Hmm… Does it update the health properly on the side tab?

I guess, no idea. The thing that goes through my mind that this spell stacks in contrary to the tooltip text. Meaning it gives 5 armour, but not setting your armour to 5