Settings reverting to default on their own

Our students are using Kami within Canvas on Chromebooks. Kami has been added as an extension to all user accounts. When students sign in to their accounts the first time, teachers have them set their settings to automatically load files in Kami. There is not a save changes that we are aware of, assume once the box is checked it should stick. However, we have several students having to repeat this action when they try to open PDF files from their Canvas assignments.