Post published, editable, but cannot access by permalink

I’m new to WordPress, have been figuring it out… until I came to one post that I just cannot reach by its permalink. If I edit the post, the permalink specified at the top (automatically generated) is the one I try to use. If I navigate to it from previous or next posts, or out of the recent posts list, our try to view the post from the dashboard “All Posts” list, all indicate that they are trying to use the specified permalink, but all fail. When I type a keyword in the subsequent search box, the post is found (or at least the first part of it, of course). However, when I click on the permanlink of the found post… it fails to link to the full post.

The only thing about the post I can see that is unusual is that the title that the permalink was generated from has punctuation in it – is this a factor? For example “Kennedy, James O’Connor” will lead to a slug of kennedy-james-oconnor which seems entirely reasonable. But in my case the post cannot be found with such a permalink/slug.

Since I can edit the post, I have tried editing it and updating, but that has not changed the link. How can I fix it?