When you click “Remember me” on a sign-in page, XtraMath uses the browser’s “LocalStorage” system to remember your sign-in information. (If you are using the mobile app, this information is stored as app data.)
If your browser does not allow websites to save data, these sign-ins cannot be remembered. Common causes for this are school IT settings (such as wiping browser data every night), or using Private Browsing or Incognito mode in the browser. These settings affect only remembered sign-in information, and the rest of the program works as normal.
If your school is blocking LocalStorage but uses Clever or Google SSO for its students, you might consider using that SSO solution for XtraMath student sign-in.