Any browser, doesn't matter because the problem is with vanilla
You start typing, the site saves a draft, you post, oh no now you have a draft, you delete it and make another post but nope, still got that draft. Sometimes two drafts!
Yeah, having a draft feature is useful, but the current Vanilla implementation is lacking. Specifically, the inability to delete our draft from the thread page. Currently, my workaround is to overwrite my old (usually poorly thought-out) draft with the letter q, but then I often forget to erase the q when making a new post (usually when I'm quoting someone).
the inability to delete drafts from the thread page has always been an issue that isn't seen as important enough to bother with but recently drafts have been getting very buggy with saving posts you've already submitted as drafts as well
Posts
Turn off drafts. Be brave, toggle that button.
https://forums.penny-arcade.com/discussion/244153/contents-of-saved-drafts-dont-leave#latest