Incorrect Provisioned Space Reported

Hard to say much without knowing significantly more about your environment, but probably the data in the DB matches, and the data being selected in the ui is the wrong selection.
If it's not that, then i'm surprised

No, the value that's shown in the UI corresponds to the value that's being stored in the database under the related column in the appropriate Datastores table.  That value in the database doesn't seem to correspond to anything that can be found in our environment. 

Without knowing anything about your environment it's hard to say anything, other than usually its a issue of what's being counted mismatching with expectations. Not sure what's being counted, not sure what's being expected, but usually that
Possibles: MB vs MiB
People expecting a filter that's not present
Counting more than one thing when you're expecting 1 thing to be counted

Might help to post some screenshots or queries or something

Without knowing anything about your environment it's hard to say anything, other than usually its a issue of what's being counted mismatching with expectations. Not sure what's being counted, not sure what's being expected, but usually that
Possibles: MB vs MiB
People expecting a filter that's not present
Counting more than one thing when you're expecting 1 thing to be counted

Might help to post some screenshots or queries or something