I second that. Two months ago I tried to submit what I found to be a quite interesting video from 2018 and it was immediately marked as duplicate:
https://news.ycombinator.com/item?id=40798566
Checking past submissions, I saw that the last time it had been submitted was a year ago:
https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
But then, as you can see from that page, someone resubmitted the video a month ago and for some reason that one got through.