Collection milestones glitch

[humble dust]

I can not claim the milestone although I alr killed all the mobs and dont need any other

[gray sand]

Bosses needed

[balmy hare]

Now this guy will say it says enemies
And i will politely ( like dumbledore says to harry in movie ) is boss your ally

[humble dust]

if its like that , then why in the rest I could collect all of the other milestones and did not have all bosses unlocked