Kill enemies doesnt count hero?

Platform, device version and operating system:
Steam, PC, Windows 10
Screenshot or image:
Kill Elementals task is 10/30

Opponent team has 2 Elementals: hero and King Gobtruffle

Kill task is only 11/30

What you were expecting to happen, and what actually happened:
I played agains team with 2 Elementals. Hero and another troop. Only got one kill instead of 2.

How often does this happen? When did it begin happening?
Noticed it today, but havent been paying attension too much earlier.

Steps to make it happen again
Play against Elementalist hero class