All Activities Attached to Contact

We have all roles in CRM setup so that all users have access to all activities. I have a link on the Contact page to an Activities report that passes the ContactId to the report, in hopes that the resulting Activity report will display all Activity records associated to that ContactId. However, it is only displaying those Activities where the user is either the owner of that Activity record or is explicitly on the team for that Activity.
Shouldn't it display all Activities associated to that ContactId since all users can see all Activities? If not, is there a way to make this behavior happen? Users profiles have "Reporting Subject Areas" = "Team Visibility" and "Historical Subject Areas" = "Full".