You didn’t screw up the entire system! You are supposed to submit as a draft to a publication (if that is what you want to do) without hitting publish. If you hit publish after submitting as a draft to a publication, your piece gets published to your personal page but not the publication. It will show up on the editor’s list of submissions but it may already have claps and comments from readers who saw it on your home page. The editors also do not have the opportunity to choose a publication date/time — all we can do is publish. So, if your piece was published to your personal page yesterday and then I add it to Snapshots today, it will show up in date order on the Snapshots page, rather than be featured at the top of the page until something new is published.
Clear as mud, right?