Boss damage is bugged?

[Encryptions]

I have a loadout where I proc kraken daggers only in normal rahabkor. I switch to another loadout with 0 procs and my damage is a consistent 180,598. 0% boss damage, 0% crit damage, no pets equipped no aa no one else in map.
Now I add 10% boss damage that 180,598 turns into 188,625. If you do 180,598 times .1 thats 18,862 I should be doing 199,460 damage... Right? Instead I am getting 4.3% out of 10%.
Elite damage could have this issue too. Here are the ss.
Further testing it seems every 10% boss damage gives 8k damage.