(ITS#1505) Missing custom attrs after restart slapd

[juanma171@yahoo.es]

Full_Name: JuanMa
Version: 2.4.45
OS: Ubuntu 18.04.2
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (92.176.151.51)


Afeter creating custom attrs, I can see in ldap browser, but after restart sldap
daemon, custom attrs are missing (sorry, bad english)
OLC mode and mdb database


LDIF for attr:

dn: cn=schema,cn=config
changetype: modify
add: olcAttributeTypes
olcAttributeTypes: ( 1.3.6.1.4.1.8876.2.1.1 NAME 'mOL-APIKey' DESC 'API Key'
EQUALITY caseIgnoreMatch SUBSTR caseIgnoreSubstringsMatch SYNTAX
1.3.6.1.4.1.1466.115.121.1.15{64512} SINGLE-VALUE )
olcAttributeTypes: ( 1.3.6.1.4.1.8876.2.1.2 NAME 'mOL-APISecretKey' DESC 'API
Secret Key' EQUALITY caseIgnoreMatch SUBSTR caseIgnoreSubstringsMatch SYNTAX
1.3.6.1.4.1.1466.115.121.1.15{64512} SINGLE-VALUE )

after restart slapd:
ldapsearch -x -LLL -b cn=Subschema -s base '(objectClass=subschema)'
attributeTypes | grep mOL-APIKey

doesn't show anything