But now they’re gone and I have no idea how to bring them back. If I am logged out, I can see them. There are two settings hidden in Discourse about auto-unpinning or something, I disabled that, no effect. I mean they are supposed to be sticky. I am puzzled. What am I missing?
Users have always been able to un-pin a topic for themselves. This now happens automatically when they finish reading the topic. Any user can disable this in his settings, and you can default-disable this setting for new users in site settings. You can also permanently disable this feature in site settings, as explained here: