Verify each User Profile Service Application has an associated Search Service Connection (SharePoint Server)
APPLIES TO: 
2013 2016 2019 Subscription Edition 
SharePoint in Microsoft 365
Summary: The User Profile service presents URLs to end users in some Web Part and tag profile pages. These URLs are trimmed for security to make sure that users do not see URLs to which they do not have permissions. The User Profile service uses the Search service to perform this security trimming. If there is no Search service associated with the User Profile service application, security trimming does not work, and URLs are visible to everyone. Although users are denied access when they click a URL for which they do not have permissions, they nonetheless can see the URL in the search results.
Cause: A Search service connection is not included in the group of connections for the User Profile service application.
Resolution: Edit the group of connections for the User Profile service application.
Verify that the user account that is performing this procedure is a member of the Farm Administrators group.
On the SharePoint Central Administration website, click Application Management.
On the Application Management page, in the Service Applications section, click Configure service application associations.
On the Service Application Associations page, in the View list, click Service Applications.
In the Web Application/Service Application column, click the User Profile service application for which you want to edit connections.
In the Configure Service Application Associations dialog, select the Search Service check box, or select Default in the Edit the following group of connections list, and then click OK. By default, all connections are included.