(I tried getting an an answer in the Troubleshooting section, but zero response. So I'll try here:
Important bug found. Can someone try and duplicate?
1. Create a post and create a slug that is different than the post title.
2. Save draft.
3. Click the Post Slug Edit button to open editing field.
4. Do not change the slug, then click cancel
5. Save Draft.
Now the post slug is returned back to the words in the post title, instead of the slug you changed it to.