MySQL 8.0 中，union 查询结果排序与 union 顺序不一致，如何解决？

select  
`id`
,`class_id`
,`active`
,`add_time`
,`show_time`
,`url_prefix`
,`subject`
from `glfr_article`
where
`active` = '1' 
and `show_time` < 1655278257
and ( `subject` like '%mysql%' or `subject` like '%导入%' or `subject` like '%导出%' )
order by 
case subject like '%mysql导入导出%' when true then 0 else 1 end, 
case subject like '%mysql%' when true then 0 else 1 end, 
case subject like '%导入%' when true then 0 else 1 end, 
case subject like '%导出%' when true then 0 else 1 end
;

SELECT  
`id`
,`class_id`
,`active`
,`add_time`
,`show_time`
,`url_prefix`
,`subject`
,(length(replace(replace(replace(subject, 'MySQL', 'MySQL_'), '导入', '导入_'), '导出', '导出_')) - length(subject)) as 'point'
FROM `glfr_article`
WHERE
`active` = '1' 
AND `show_time` < 1655278257
AND ( `subject` LIKE '%MySQL%' OR `subject` LIKE '%导入%' OR `subject` LIKE '%导出%' )
ORDER BY 
length(replace(replace(replace(subject, 'MySQL', 'MySQL_'), '导入', '导入_'), '导出', '导出_')) - length(subject) desc