Valid UID contextual filter not updating page title

I have a page view to display content of fields created by a user. The user name is passed to the first contextual filter via the URL (my-view/%). There is a relationship of Author in the view.

The first contextual filter is a Content: Author uid, with the following options set:

When the filter value is NOT in the URL:
Display all results for the specified field

When the filter value IS in the URL or a default is provided:
Override title: %1
Specify validation criteria: Checked

Type of user filter value to allow: Only allow string usernames

Action to take if filter value does not validate: Show page not found

Expected behavior: When viewing the page and passing it a valid user name via the URL (my-view/admin) the content should filter to only that created by the user and the page title should be changed to the username (admin).

Preview: When entering a valid user name in the preview textbox, the content filters and a ""title" appears with the user name as specified.

Actual behavior: When viewing the page and passing it a valid user name via the URL (my-view/admin) the content is filtered to only that created by the user. The page title does not change.

If the view was not recognizing the user name and validating it, it would be displaying all content; the filter is accepting the parameter and it is working properly as a filter.