Why do women suddenly switch up on a person?

I went out this girl and we had a pretty good time laugh, joked, etc. We really got to know each other. Then we went out again and also had a great time the thing I don't get is that she is a dry texter but holds a conversation in person. Then I tried to set up more in-person hangouts and suddenly started to be too busy and Ignored me. Why do women do such things when I see based on interactions we had we are going in a great direction?
Why do women suddenly switch up on a person?
Post Opinion