A small number of reposts is ok if a story hasn't had attention yet. This is in the FAQ: https://news.ycombinator.com/newsfaq.html. This is to mitigate the randomness of what gets traction, because otherwise too many good stories would fall through the cracks. Lots more explanation here:

https://hn.algolia.com/?sort=byDate&dateRange=all&type=comme...

https://hn.algolia.com/?sort=byDate&dateRange=all&type=comme...