I have just installed two Vcenter 6.5 systems and they are in linked mode. When I login with the administrator@vsphere.local account and all works fine. I have setup the SSO and I can login with my user account but the linked vcenter does not appear as a linked system? I seems like when I am logged in as the administrator@vsphere.local account the SSO information is the same on both systems.
Any ideas what to check?