This issue is most often caused when a user does not go through the complete voting process on that web site. Be sure you follow through with all the steps on the site. Sometimes it may appear completed but still require one more click. Ultimately there is nothing we can do though. We do not run that web site and cannot control if it gives the wrong response to our plugin. Our plugin just pings it asking if you have voted when you type the /vclaim command.  The web site just answers yes or no, we cannot alter what it answers or manually override it as we do not own that site or have any ties to that site.