Some plugins are distributed under a bulk license, and the plugin you are trying to update is one of them. Since the theme developers have not uploaded the new version of the plugin to their servers for distribution, you cannot update it yet. After some time, you will see that the updated version of the plugin is available for download. Normally, the license fee for the plugin you are trying to download is on par with the theme price. Xtemos generally strives to keep the plugins up to date. As long as there are no security vulnerabilities, there is no need to worry.