With the sluggishness of the site these last few days you can sometimes get slowness or infinitely loading icon when hitting submit. If you aren’t sure if your post submitted, refresh the original page in a different tab before hitting submit again to see if it went through. I see double and triple posts in almost every comment section.
I said I was sorry… Gosh
Resubmitting is the reasonable response to an error that said it failed. Lemmy should add some sort of duplicate message prevention when they have the time to improve the ux.