She's super interesting and flirty irl but never really texts back?

So basically, I have a co-worker who i click with. Im always making her laugh, and we've flirted quite a bit. But that seems to be our dynamic at work. She mentioned to me multiple times that she's single and left obvious hints. But I struggle expressing myself. So I have her number now, and I text her here and there. But she rarely replies, and sometimes she leaves me on read. Im confused about this situation.
She's super interesting and flirty irl but never really texts back?
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