Why did timezone become `SYSTEM` about typeorm HOT 2 OPEN

// the code here, don't use await before query.
 const timezone2 = await DB_DEFAULT.query('select @@session.time_zone;');
console.log('==timezone2', timezone2);

DB_DEFAULT.query(
            'SELECT `AdminUserModel`.`id` AS `AdminUserModel_id`, `AdminUserModel`.`createTime` AS `AdminUserModel_createTime`, `AdminUserModel`.`updateTime` AS `AdminUserModel_updateTime`, `AdminUserModel`.`status` AS `AdminUserModel_status`, `AdminUserModel`.`nickname` AS `AdminUserModel_nickname`, `AdminUserModel`.`contact` AS `AdminUserModel_contact`, `AdminUserModel`.`roleIds` AS `AdminUserModel_roleIds` FROM `adminUser` `AdminUserModel` WHERE ((`AdminUserModel`.`id` = ?)) LIMIT 1 ',
            ['28'],
        );
DB_DEFAULT.query(
            'SELECT `AdminUserModel`.`id` AS `AdminUserModel_id`, `AdminUserModel`.`createTime` AS `AdminUserModel_createTime`, `AdminUserModel`.`updateTime` AS `AdminUserModel_updateTime`, `AdminUserModel`.`status` AS `AdminUserModel_status`, `AdminUserModel`.`nickname` AS `AdminUserModel_nickname`, `AdminUserModel`.`contact` AS `AdminUserModel_contact`, `AdminUserModel`.`roleIds` AS `AdminUserModel_roleIds` FROM `adminUser` `AdminUserModel` WHERE ((`AdminUserModel`.`id` = ?)) LIMIT 1 ',
            ['29'],
        );

const timezone3 = await DB_DEFAULT.query('select @@session.time_zone;');
console.log('==timezone3', timezone3);