I would blame the director/script and not the actress, honestly. Also, for someone who was marketed as a "hologram/CG" singer, she's actually doing something.
As for the lack of stage presence, as I said she had an aura and some speculation as not being real, as a CG creating, and the only live performance she did since her debut is this:
... which you can barely see her because she's behind dozens of mirrors. She has no stage persona because she's barely a performer still, so putting things into consideration, she's not great, but she's better than I was expecting.
I still haven't watch a full episode, I will wait when it's all over.