Yup. I'm shadow banned on twitter. When I like something, often the like count goes down unless I click on the post itself. It doesn't even have to be GC stuff, could just be a popular animal pictures account or something. It's clear I am flagged by twitter because of who I follow, who follows me, what I (mostly) like, what I tweet and retweet, etc.

Is that what that is??? I've noticed that when I like tweets as well.