It’s called shadow banning.
You think you’re rolling along, pinging all of your followers, but FB or Twitter has actually blocked your posts from going out.
A coworker of mine did a test. Set up two twitter accounts and would post on each, to each and to others. Her more pro-Trump account wasn’t pinging/posting. Her more generic account was cruising along just fine.
Not being a social media person I didnn’t know what it was called. Thanks for the information.