Issue trying to copy a post from reddit

I'm trying to preserve a great write by dbclick on reddit from a few years back before it's taken by the enshittification, https://www.reddit.com/r/FFVIIRemake/comments/g75lfj/quit_acting_like_you_know_me_the_evidence_against/

I have the raw markdown text of the post from res I edited. It shows up perfectly in the Lemmy preview, but when I try to post it to one of the final fantasy communities I get "Error: invalid_body_field" any clues?