"I joined Pixelfed and my first post was set to Public but minute or two later it was set to Unlisted, what's going on?"
You trigged our anti-spam detection system, don't fret though!
Your post is awaiting review by a human admin who can mark it as not spam and restore the Public visibility!
Not all :pixelfed: servers have the anti-spam service enabled, those that do use it to keep the public timeline free from spam.
It isn't personal, unless you're a spammer ❤️ #pixelfed #spreadTheWord