attachment icon (paper clip) disappears once message is opened

We're having what appears to be random issues with the paper clip icon disappearing from an archived message.  Once you go to message and highlight it, the icon disappears.  Opening the message, the attachment is there and can be opened.  However the paper clip icon is gone. 

We've uninstalled and reinstalled the add-in.  This did not resolve it.  I've provisioned and synchronized the mailbx.  This did not resolve it. I've ran the archivng task, this did not resolve it. 

Any ideas?

Thanks Much.