Not sure if that's the case, few of my hn posts do get de-ranked on hn very fast such as [1] and [2]. If you can prove it using
https://news.social-protocols.org, you should report it to hn@ycombinator.com
[1] https://news.social-protocols.org/stats?id=50102854
[2] https://news.social-protocols.org/stats?id=50068946