Instructor Capabilities On User Profile Page Not Saving When Granting/Revoking Capabilities

I am trying to give an administrator user account Instructor Capabilities on the edit user page. I have selected the Radio button to grant them instructor privileges and click the save button at the bottom of the screen, but the page reloads and doesn't save that change. I have seen that all the other information on the page I entered at the same time saved properly.

I have disabled all plugins (except for CoursePress Pro) and tested using the themes Twenty Fourteen and Twenty Thirteen, but the radio button will not save. I have also tried disabling and re-enabling the coursePress Pro plugin, but it's still not saving.