You paste a chunk of Markdown into a Jira description and get exactly what you pasted:
literal ##, literal **bold**, list items on one line. Nothing is
misconfigured. This is the expected behaviour.
Jira Cloud's Markdown handling is autoformatting: it reacts to characters as you type them, one pattern at a time. A paste delivers the whole document in a single event, so there is no sequence of keystrokes to react to. The text is inserted as text.
The underlying reason is the one from the support question: Jira stores ADF, not Markdown, so pasted characters have to be interpreted by something before they become structure. On paste, nothing does that job.
Render the Markdown to HTML first: any Markdown preview will do, including your editor's preview pane or a README view: then copy the rendered text and paste that. The editor accepts rich text from the clipboard, so headings, bold, lists and tables usually survive.
Check tables and code blocks after pasting. They are the two that most often come across flattened.
For a short description, paste the plain text and then retype just the markers: put the
cursor at the start of a line and type ## plus a space, or - plus a
space. Autoformatting fires on those keystrokes and converts the line.
This is tedious past about ten lines, but it needs nothing installed.
Marketplace apps add an editor that takes Markdown as input and writes native Jira content back. Paste your document in, save, and everyone else sees a normal formatted description without installing anything.
This is what our app does, and it is why we built it: see the box below.
Comments use the same editor and behave the same way. Autoformatting works while you type; a pasted Markdown block does not convert.
These notes are written by sellerkit. We build a Markdown editor app for Jira (below), which is why we had to work all of this out in the first place.
Everything above this box works whether or not you install anything. Where a workaround is enough, we say so.