Ask HN: I my submission resulted in odd error (or shadowban)?

I attempted to submit https://www.infoworld.com/article/3440557/should-open-source-licenses-fight-evil.html

Normally, when you submit a URL that has already been submitted, you are taken to the original submission, and its score gets incremented. In this case, it took me to an error message: "This story has already been submitted". Why did this anomaly happen?