MSDP Clean up

Hi,

One of our customer is experiencing a problem with their MSDP.

Upon checking, reamining available space of MSDP is at around 1 TB and they do have scheduled backups that are running.

As per customer, all images from the catalog and MSDP are already expired but no space were freed. 

I believe MSDP runs a clean up but how come no additional disks are allocated and the expired images are still at MSDP?

Thanks!