I suspect that OCUM is having an issue monitoring or polling this one device. Since the data in the WFA cache is loaded from OCUM, if OCUM has an issue collecting the data, then it will not be reflected in WFA. Try logging into OCUM and see if the new volumes show up. IF they do, then check your WFA Data Source, if they do not, then troubleshoot the connection from OCUM to the filer in question.
Mike