See attached image for example (not my post). The other day, I posted something and received an error (can't post or something along the lines). I was returned to my draft and pressed post again. This time, the post went through. However, it now turned out to be posted twice, despite the initial error message. Why does this happen so frequently with Lemmy?
This used to happen on Reddit all the time. It's a matter of error handling correctly, either on the Lemmy instance itself, or the app you're using to interact with it. This is a growing pain that will hopefully sorted out in the future.