Follow churn rates sudden drop?

Hey folks, recently noticed my follow/unfollow churn (white hat technique within ToS, follow within limits, don't unfollow for 3 days, all above bar) has received a sudden and SEVERE drop in return - where ~300 follows were returning ~100+ followbacks, its not returning more like ~5

This occurred a few weeks ago and began affecting all accounts I perform churn on simultaneously. My guess is there have been some changes to Twitter which have negatively impacted churn, maybe they no longer send users push notifications for follows or something like that? I wanted to see if anyone knew of any recent updates that would affect churn, and how you were pivoting to deal with the changes?

Hoping this may evolve into a conversation on Twitter growth in general

Thanks!