And it even turned out to be that bitch no wonder she was so ungrateful she was trash in the first place...
I went back to re-read chapter 1, and there's nothing she does in the small part in which she appears that warrants calling her a "bitch" and "ungrateful". She's just a VA that wants to do singing stream and other stuff, and is forced by their boss to only voice the MC character.
Anyway, the MC was a piece of work, so what's wrong with her being unhappy with his behaviour, when it's affecting her own job? She's not the one that selfishly go off script out of pride and costs both of them their job.