In some cases, clearing all data to the app and restarting the phone may be a solution. This is only possible on Android phones, a similar solution to an iPhone requires reinstalling the app - completely delete and reinstall the app.
If you have an Android phone, find the app in your phone's settings:
When you open the app again
When you reopen the app, you will be greeted with the welcome greeting and you will have to give various permissions and reset alarms as the app has forgotten everything.
Why not just reinstall the app?
However, it is not the same as uninstalling the app, as this means that you need to reset the phone settings for the app, and you may find that not all data from the app has been removed, therefore this method is useful in certain cases.