What's the result of these queries in your database?
SELECT *
FROM TABLE(AUTH_LIST_AUTHORITIES_FOR_AUTHID('DB2ADMIN', 'U'))
WHERE AUTHORITY IN ('DBADM', 'CREATETAB', 'IMPLICIT_SCHEMA')
;
SELECT GRANTEE, GRANTEETYPE, DBADMAUTH, CREATETABAUTH, IMPLSCHEMAAUTH, SECURITYADMAUTH
FROM SYSCAT.DBAUTH
WHERE 'Y' IN (DBADMAUTH, CREATETABAUTH, IMPLSCHEMAAUTH, SECURITYADMAUTH)
;