If you change a title or subtitle after publishing, the preview of your story usually retains the old title or subtitle unless you go in and change them as described. Weird and illogical. The Description section is actually useful, as it shows up in online searches. But you have to use the “…” menu to access it. So it is a debatably useful feature I am sure many Medium writers don’t realize is available.
Don’t get me started on the mobile apps quirks and frustrations.