PDF Learning Activity not being marked as complete

Summary:

Before the 25A upgrade, we launched a course that includes only a PDF. To mark the training as complete the learner just needs to open the PDF.

Some users have been able to complete the training, but other users remain in the "Not Started" status despite completing the training.

When I go to Manage Activities for someone who believes they have completed but they are still in "Not Started", it does say they have completed.

Any suggetions?

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

25A

Code Snippet (add any code snippets that support your topic, if applicable):