Why are backups kept locally after transferring to my remote backup destination?
This is generally caused by the following option is enabled in WHM
Home »Backup »Backup Configuration
Retain Backups in the Default Backup Directory
The description for this option provides a bit more insight into this:
Retain backups in the default local backup directory, even after the system transfers the backups to another destination.
If you disable this option, the system will delete the backups after they move to another destination.
This option can be disabled via WHM
Home »Backup »Backup Configuration which will allow the backups to be removed after they have been successfully transferred.