According to the Bugzilla article, NSS upgrade breaks openldap, there is a bug in NSS version 3.27 which will cause LDAP connection failure, and it is fixed in NSS version 3.28.
IMSVA Patch 3 has upgraded NSS to support LDAP over TLS1.2 (LDAPS). After applying IMSVA Patch 3, users who are using OpenLDAP server with Name Service Switch (NSS) version older than 3.28 may experience LDAP connection failure.
To prevent this issue from happening, upgrade NSS on the OpenLDAP server to NSS 3.28 or newer version.