DA - Hovering, Orbiting, Peacock Behavior

I triggered the DA I was seeing for a short time with a break up and confrontation of their behavior. He deactivated and stonewalled me. Found out he was monkeybranching and was starting to see someone either during the flakey behavior, or immediately after our breakup. I made it clear I do not want to be around him, or see him when unnecessary during the breakup because we still have to see eachother at work. He was heavily avoiding me at first. 2 or 3 months in, he would peacock when in group settings that we could not avoid. He would orbit or linger when we forcibly had to be in the same area. For the last few months we have been able to avoid eachother almost completely. Now, about a year later we cannot as much and he is escalating. Getting more comfortable and intentionally inserting himself in my spaces, talking to people he usually does not in proximity. He peacocks and says things out loud that seem he tries to get a reaction out of me. Why do avoidants do this? What does he want and why is he no longer respecting the space? How do I get him to stop without giving him the reaction he desires and allowing him to rewrite the narrative that everything is "okay" and he did nothing wrong? I think he wants to get a reaction out of me to prove he still has an affect on my emotions, or he wants to sooth his guilt.