Why is my friend ignoring me all of a sudden?

We’ve been neighbors for about five years and we get along. This girl (let’s call her Christine) who lives with her parents and younger brother. Christine is 19 and I’m 22. Her and I used to hang out a lot sometimes and she introduced me to her friends. (She was 14 and I was 17). We hung out. I didn’t have much friends at school. I know the pandemic was hard for us to hang but we did video chats, walked around and not much. Lately I haven’t been seeing Christine too much. It’s been months and I didn’t see her at all this summer. I asked her parents and they said she’s been out of town this summer. I’ve texted her, went over but she’s either never over or don’t respond to my text.
So last weekend my neighbors came over and Christine came by. I was excited to see her but I noticed she didn’t go over to hug me. I went over there but she just walked off back to the house.
I was like….. okay. Then later she came back. She talked to my parents and my older siblings but she ignored me. I tried to strike up a conversation with Christine but she just grabbed the basketball, walked off and played with my cousins. I said, “What’s up? Why haven’t you called me?” Christine just looked at me and walked off. That was very rude so I gave up. Then today as I was driving up the parking way at my house, I waved at her and her bestie, but they kept talking.
I know Christine saw me wave but she didn’t respond. I don’t know what the hell is going on. I didn’t do anything to her. Maybe I didn’t go up and talked to her right away.
Last time we hung out was sometime last year and we had a blast.

Christine is hurting me.