BloodMage Life leech is not working (or all leech in the game)

I've done a quick test to show how it is right now:
https://streamable.com/f505cf
As you can see, i've leeched 20 LIFE after using my Comet which deals ~4500 damage + penetration.

Here is my Comet tooltip:

Surely that should not be 20 LIFE right? Its either leech numbers are wrong or monsters have 95% leech resistance at monster level 40.

I can confirm that this is for sure leech resistant related issue. At monster level 40 zone i leeched 20 life, at monster level 7 zone i leached ~400hp (around expected numbers from ascendancy). GGG should reconsider leech resist numbers as it is nearly impossible to leech later in compaign (and maps).