WordPress was installed on the domain when the domain had SSL/TLS Support option disabled in Domains > example.com > Hosting Settings
Advisor shows that WordPress instance is not secured:
WordPress SSL/TLS status does not update accordingly when SSL certificate is installed:
SSL/TLS flag in current WordPress Toolkit implementation shows only which protocol is used at WordPress instance configuration. If WordPress instance configured to use HTTP (both site URL and home options have values starting with
http://, SSL/TLS flag will be yellow (at ‘disabled’ state).
The following can be done in order to solve it:
Click on a section to expand
If Advisor extension is installed
Log into Plesk.
Go to Tools & Settings > Advisor > Security tab > Secure WordPress Websites section and click Secure:
Select the WordPress instance and click Switch to HTTPS.
If Advisor extension is not installed
Log into Plesk
Go to WordPress and log in to the WordPress Admin page of the instance:
Go to the Settings menu, change the WordPress Address and Site Address (URL) to
https://example.com. and click Save Changes
Go back to WordPress and click the Refresh button in the upper right corner of the instance field: