Manager Can Assign Journey to Self but Cannot See Direct Reports

We assigned the Manage Worker Journey By Manager role to a manager. The manager can access My Team > Journeys > Explore, view all journeys, create journeys, and use the Assign option.
While assigning a journey, the manager has the following Assignee Selection Type options:

• Person
• Directs
• List of Persons
• Organization
  

However, the manager can't see any direct reports under any of these options. In the Select a Person field, only the manager's own name is available.

The manager can see direct reports in My Team and My Activity Center, so the manager hierarchy and worker visibility appear to be working correctly.