Every time I watch that first scene with SS and homelander in her room and she starts talking about Rome, it makes me cringe so much. Her delivery feels really unnatural.
She's supposed to be coming off as super confident and intelligent but the way the lines are delivered, the way she mumbles her lines, feels like someone who is really nervous rehearsed these lines and is delivering then in a way that they think sounds confident.
If homelander had commented on how uncomfortable she sounds and poked fun at her for it, that would have fixed it and she would be an interesting and complex character, but the way it is, her acting just doesn't make sense and doesn't blend well with the natural acting of the rest of the cast.