In an effort not to fall too hard into the classic Reddit trope of proclaiming that everyone's partner is a bastard in these kinds of threads, I think there could be some yellow flag reasons for this behavior.
People are strongly conditioned to perform certain behaviors in social situations. Her actions could have been a result of that conditioning, especially if she is trying to be perceived as femme. That is, she's performing "flirty, fun, sexy" in non-intimate situations because it's how she wants to be seen in those moments. That doesn't necessarily mean that she's lying about being aromantic in her more intimate and less guarded interactions with you.