SSL it! extension shows
Security can be improved message on the SSL/TLS certificated button on the domain overview page if some of the security suggestions are not applied (e.g. wildcard certificate is not issued). This message is confusing since not all domains require wildcard certificates.
SSL it! points of improvement with ID #EXTSSLIT-730 and #EXTSSLIT-715 are registered. They will be fixed in the next updates.
There is no workaround at the moment.
Make sure that extension autoupdates are enabled as per this article.