I was under the impression that if you modified a post's slug, the Redirection plugin would create a 301 redirect for the old slug automatically.
I'm using Redirection 2.2.8. When I modified a post's slug using Quick Edit from the Posts list, I started getting 404's for the old URL. Looking in Redirection's WordPress Modified Posts group, there's no redirection there.
Am I under the wrong impression about the functionality of this plugin, or is something broken?