Ghost 12 - Other Used Space is not showing correct free space on backup destination

Ghost 12 is showing that a large amount of my backup destination is Other Used Space, but there is plenty of free space available on the drive. 

 

I have been through all of the related posts and solutions on this site, and tried the steps to remove history, etc.  I even got desperate and completely removed and reinstalled Ghost...  all with no success.

 

What do I need to do ??

 

 Ghost Home.png

 

Manage Backup Destination.png

 

Backup Drive Properties.png