Please deactivate your activation and then again reactivate the licence it will solve your update issue. if the theme is not activated in other sites before this site.
If you failed to activate after deactivated then need to remove that old activation from our end. In that case, inform us, we will do that.
Already activated message will show if you have installed in other site and move new domain without activation and remove that licence. In that case from our end have to remove the old site and then the customer can activate new site.