It happened to me as well! I have a history facebook page, and it covers everything historical, no discrimination. One of the topics was about Hitler, with a picture to go with it. FB banned me from posting for 3 or 7 days. They actually banned my facebook user account attached to the from posting anywhere on FB, but kept the page going.
It wasn’t reported, I think they used some sort of algorithim, made a new jerk reaction and bam! But losing an entire page – now that is just bad.
Just like you – didnt break any terms. No recourse either.