Spotfire Server 7.13 Server Configuration Tool uiconfig terribly slow on load current configuration after LDAP users import

I have noticed as the tool takes more than 3 minutes to load the actual server configuration, such slowness appeared after I set the Active Directory LDAP Authentication and User Directory and imported all users. The total number of users imported is approximately 40000. My server is clustered with a backup one using Apache Ignite. Still not sure if is the number of users the ultimate cause or other factors. Anybody has experienced situations like that? Searching on the community and with google I did not find very much thing so far..

Thanks in advance