DeDup disk showing 0 bytes free (only when you try and select it for a backup job)

my dedeup storage disk is showing 0 bytes free (only when you try and select it for a backup job) causing jobs to fail.

when you click the storage tabe it shows over 1 tb free

when you look in explorer it shows the same amount over 1tb free.

any ideas?

i have already done an inventory and a catalog.

thanks