MySQL Enterprise Monitor 8.0 Release Notes
On startup, the agent sets sql_mode=STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION,NO_AUTO_CREATE_USER on the monitored MySQL instance. If sql_mode=ONLY_FULL_GROUP_BY, agent queries can fail. The local agent of MySQL Enterprise Service Manager also sets sql_mode=STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION on the repository.