When I stop and start the slapd service the latter fails with : Aug 12 11:33:17 ldap1.domain.com slapd[30972]: @(#) $OpenLDAP: slapd 2.4.44 (Jan 29 2019 10:05:51) $
It means that there is no match between what you defined as the URI's associated with olcServerID and the -h argument to slapd, so it cannot link a serverID to this instance of slapd.
--Quanah -- Quanah Gibson-Mount Product Architect Symas Corporation Packaged, certified, and supported LDAP solutions powered by OpenLDAP: <http://www.symas.com>