What's up with a guy ignoring girls he dated at all costs?

It’s puzzling to me that a guy I was seeing a year ago whom I suspected had avoidance issues started to talk to me again and showing up at mutual meetings. For a year, since we ended it, he avoided me. He skipped all the meetings for school just to avoid me. He would go out of a store if I’m shopping there. He told friends he hated me and begged them not to talk about me meanwhile he just was doing all he can to not face me.

I heard from a mutual friend that when his girlfriend of 4 years broke up with him BECAUSE he was avoidant, he went to a different continent/Russia for a year without tellings anyone and all alone.

I’m not a psychologist and probably neither are you, but any thoughts on this bizarre behavior?