⏰ In A Nutshell
Check if the mp3 file is deleted or if the app does not have access to file storage.
⏰ To Elaborate
If you are trying to use an mp3 file as your alarm ringtone, the default alarm ringtone comes out when the phone is unable to read the mp3 file.
Please check the following.
- If the mp3 file is deleted
- OR Move to [Setting > Applications > Alarmy > Permissions] and check if access to internal file storage is allowed.