Previous backup location still is the default or
Individual jobs haven´t updated to the new location.
To view the Backup Service preferences:
1.From the Management Console workspace selector click Configuration.
2.Select the farm for which you want to set the Backup Service preferences.
3.From the Configuration tab, click Backup Service.
4.Select the new backup path and ensure that it is the new default.
5.Go to the Scheduled backups tab in the top
6.Select one of the jobs and click on edit.
7.Go through the steps and ensure the path selected is the updated one, click on next to leave existing settings as they were and save it.
8. Repeat for any other scheduled job.