【Updated: 】
If you don't view the results for a ranked cup you participated in, and then don't log in during the tour following, you will be treated as the lowest rank (rank 20) for the last ranked cup you took part in. That lowest ranking result will be reflected once you open the app, and your tier will be lower than it was for the last ranked cup in which you participated.
Note: If this is the case, you will not see a results animation.