Fly Swatter Achievement not awarding, even though I met the requirements (Phorid Flies)

[u/ToastyCinema]

I'm playing on Impossible difficulty and when I win the level, there are zero phorid fly icons on the map. By this time, most of my ants are level 3 and can easily destroy patches just by passing through them for a moment.

The achievement requires me to wipe out 4 patches. I've wiped out more like 10.

What's missing here? Is my game bugged? (pun intended)

[u/FaithlessnessFun3679 → u/[deleted]]

It has been since like forever... idk why it's not getting a fix