Guardian of Meletis bug

So, against Guardians of Meletis (Chapter 1, Part 2, fight 9), the third objective is to kill 6 or more enemy creatures. Simple and straightforward enough, but after 20 minutes of killing his single creature, using a combination of Rolling Thunder, Scour From Existence, Cobblebrute defenders to kill his creatures, I found one big problem. I had to have killed at least 3, maybe 4 creatures. Problem?

None of them counted. My counter for how many enemy creatures I killed remained at 0. This has happened in this fight several times. Why can’t I beat this objective?

This seems to be a bug with all “kill X creatures” objectives.

Some kill X creatures objective are just wrongly displayed, cause in effect it mean “have X of YOUR creatures die”

Try to see if that’s the case(after your creature dies check the amount of “kills” through pause menu.

That’s not it for this fight. One way I killed one of their creatures was reinforcing Cobblebrute enough to kill their creature, but my creature died too. Still zero.

Do not know then, I checked and all I can say is that I did it already(in the past).

So either it bugged with some patch or there is a way to do it but I cannot help in finding out how.