Realm app.allUsers problem

Hello, I am developing mobile app and I wanted to have page that shows all users that have logged at some point on that device. I tried to implement that by using app.allUsers to get all users authenticated on that device, the problem is, it works if I am in app and I first login than logout and if I go back to that page user will be there, but when I close and open that app again app.allUsers is not persisted, I need to login again in order to access that user via app.allUsers, what am I doing wrong?