It is now, but shortly after submission, when it had made it to the front page (10ish votes and 3-4 comments in 10 minutes) it just vanished from the front page

It is now, but shortly after submission, when it had made it to the front page (10ish votes and 3-4 comments in 10 minutes) it just vanished from the front page -- not on the 2nd, 3rd etc. It was still on the "new" page and not marked as [dead] nor [flagged]. I'd not seen this kind of "shadow banning" before, and seems an odd target for it: the discussion is generally respectful, not that much shouting ...