how to stop auto-posting old articles

All of a sudden we've noticed that old posts are getting auto-posted if we make an edit to the old post or add a tag, etc. We've been using UF for over a year and it seems that this has just started recently. We are running 2.8.1 on WP 4.3.1 and have noticed this on two different sites, so it's not a fluke. Any pointers of what to check? I've attached our settings.