Culling strikes do not work (witch hunter AND support gem)

Witch hunter passive "Pitiles killer" does not work at all.

Support gem Culling strike I :
- doesnt work for : high velocity rounds , crossbow shot
- does work for : armour piercing rounds

If needed, I can show screens or record it.
Even when culling strike seems to work, which only happens for armour piercing rounds, there is no blue orb indicator like I remembered from a monk skill.