Best friend blocked me out of nowhere?

We haven't even spoken in months, and we've just graduated college but I haven't seen her cos she's been away. We've had our ups and downs yes, I'm dating her ex from years ago and there was a small thing where I went after the guy she liked, but that was barely an issue because he didn't even date her anyway and that was a year ago. We've really been getting on this year and our friendship has been amazing, we even got each other really cute birthday presents. But we've just graduated and I've seen she blocked me on all social media. What the hell. Should I contact her and ask her why? Is she being a bitch?
Best friend blocked me out of nowhere?
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