Look like duplicate post of https://lemmynsfw.com/post/3413165?
It is. Sometimes when uploading, the connection will freeze for a few minutes (up to 10 is worst case I have seen). When that happens just after you hit create, you will get duplicate posts. If you delete one, the other one goes as well. Seems to be random which post most people will see. The upvote/downvote count increases on both posts, but not in sync. I would try and report it as an issue, but that does not go so well for me.
Interesting - yes I’ve encountered the freezing and duplicate posts , especially when using app ( I use “boost for Lemmy” now). I was not aware of the up/downvotes counts aspect as I generally end up deleting one of the duplicates as soon as I see it.