Are those downvotes maybe coming from non-Lemmy instances?
As an admin you should be able to see the downvotes of the post that made it to your instance.
I'm wondering if some software might be broadcasting votes to all linked instances, while I believe Lemmy only sends them to the community instance and it's the community instance's responsibility to relay them.
won't be the case for much longer, the next lemmy release is removing that.
i suggest you remove this quote and summarize it with fewer details if you need to have it there in the first place. you're effectively advertising for them now and undoing the moderator action of removing this advertisement.