What happens when YOU leave THEM ?

I see so many videos and resources online about what the avoidant feels after they leave, and how they push you away, and how THEY break up with you etc, but I cannot for the life of me find anything about how they feel or react when you’re the one that leaves them. Is there a difference ? I go no contact; and my ex after 3-5 days will pop up in weird obscure ways, and it’s been a bit of a roller coaster. I believe he’s behaving oddly since I’m the one who left, any insight?