Girls, Why is she acting distant but only making small talk to with?

My friend at work is acting distant towards me ๐Ÿ˜” she is basically not saying hello to me or if not hardly. She and I got alone really well and talk everyday. Why is she treating me differently? I've tried talking to her and she says everything is fine and that I haven't done anything to upset her. But she keeps acting this way. It's actually starting to upset me and make me feel bad about myself. But for some reason she keeps asking if I'm ok which is weird.
Girls, Why is she acting distant but only making small talk to with?
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