This happens due to there being 2 or more SAR's in the history.
The client would have signed the oldest version, but the process that picks up on the SAR only ever looks at the newest version.
To fix this, identify the CLSARS document in the history that has been accepted.
Make a note of the document code.
Then go to the Compliance Dev Only - 'Compliance Admin' screen.
Press the button "SAR Fix" and enter the document code.
All sorted.
Let the requester know that it has now been sorted and they need to generate the document again and it will pull through the signed version.