I do not know why it DOES HAPPEN but definitely it happens, I have not really unfollowed anyone every LOL well once I blocked Pechi by mistake hahaha LOL on my small phone hahaha but I really do not even post so often, I get in and check my feed but of course it shocked me I had to refollow.... well hahha as many times as needed, I am though intrigued by it... I once "unfollowed" Serena, and come on we are best friends LOL knowing that if it ever happens know it is not on purpose