Lost drafts off Quick Draft

I lost a major thought piece that’s hard to recreate. Preamble, 6 points, summary, call to action. Yet a short dummy heading post was saved.
I’ve just done a short test; while WordPress was saving I clicked to another tab (which normally means the existing tab is still active. Draft lost.
Another, waiting to see Save execution complete. red bar ran down the draft list on the dashboard page but nothing saved. Clicked to ‘view all’ page to check; red bar ran down the page, nothing saved.
Tried again with a post containing a paragraph; not even a red bar to indicate anything, though the dashboard page did flicker indicating reload – without the new draft on the list.

WordPress 3,8.2 with Mexin theme.

So is there an automatic data save function even if it doesn’t display on the list? Is there an autosave?

This is major: the whole point is speed and capturing content to share. Quick Draft fails. Please fix.