So, this happened today... I noticed if you post a steemit link as a reply to a comment on a verified page on Facebook. It will actually flag it as spam. sometimes it will even put a button that says "not spam?" and says thanks for your feedback if you click it.
But try to post the same link from Youtube and everything is hunky dorey! no problems.
I didn't test or play with this too much, So all I could deduce for now was that it is happening on verified pages but it could be more and only to replies of comments? But I don't think it is limited to these scenarios.. There is clearly a smart algorithm going on behind the scenes doing something bad here.
Wow!