Why does this ex toxic friend try to contact me over social media a year after I cut off all contact and blocked her?

I was friends with this girl, and she became a toxic friend, so I decided to cut myself off from contact

The reason I decided this was because she was always angry and snapping at me, and it became very unpredictable and I often felt like I’d be walking on eggshells. She also said things to hurt and upset me, for instance when we both bumped into my ex, she would tell me he didn’t even acknowledge my presence when I walked past him. She also pointed out to me on a separate occasion when we met my ex’s friends that they ‘completely ignored me and acted like they hated me’ and that really upset me

When we were both invited to a wedding, she tried to separate me and stopped me from talking to anyone except her, and embarrassed me in front of the guy I fancied by inviting the guy I liked over to hers for champagne in front of me. She also kept coming out with remarks such as ‘I look like a troll compared to you in photos’ and she kept wanting us to take photos together and kept asking me to stand in a corner so she could take my photo.

I found the only way was to block her number. She then called me on two different numbers after I had blocked her and sent me a voicemail asking me to get in touch with her. After I didn’t get back in touch she showed up one evening at my social group. The entire night, she was glaring at me as if she wanted to hurt me. And she made a passive aggressive comment about how she wished friends ‘had her back’

Exactly a year later she finds me on social media and sends me a private message, with an aggressive message saying ‘I’ve tried to contact you but I’ve not heard so I’m going to stop now, have a good life’. After this, a month later she starts sending me other messages, copying links of videos I would like and sending nice messages to me. She also followed my account on social media, but I haven’t accepted her because I’m weirded out by it all. She also called me twice.

Why is she STILL trying to contact me after I cut off all contact?
Why does this ex toxic friend try to contact me over social media a year after I cut off all contact and blocked her?
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