[Solved] DB collation issue after updating to 7.0.0

Hi @tomson. The error has not disappeared despite me clicking the "Fix Tables" button for the 3rd time. It states:

[Illegal mix of collations (utf8mb4_unicode_520_ci,IMPLICIT) and (utf8mb4_unicode_ci,IMPLICIT) for operation 'like']
SELECT
`c`.`comment_author_email`, `c`.`comment_author`,
COUNT(`c`.`comment_ID`) AS `count`, IFNULL(`s`.`count`, 0) AS `scount`,
IFNULL(`fi`.`count`, 0) AS `ficount`, IFNULL(`fw`.`count`, 0) AS
`fwcount`, MAX(`c`.`comment_date_gmt`) AS `last_date` FROM `wp_comments`
AS `c` LEFT JOIN (SELECT `email`, COUNT(`email`) AS `count` FROM
`wp_wc_comments_subscription` WHERE `confirm` = 1 GROUP BY `email`) AS
`s` ON `s`.`email` LIKE `c`.`comment_author_email` LEFT JOIN (SELECT
`follower_email`, COUNT(`follower_email`) AS `count` FROM
`wp_wc_follow_users` WHERE `confirm` = 1 GROUP BY `follower_email`) AS
`fi` ON `fi`.`follower_email` LIKE `c`.`comment_author_email` LEFT JOIN
(SELECT `user_email`, COUNT(`user_email`) AS `count` FROM
`wp_wc_follow_users` WHERE `confirm` = 1 GROUP BY `user_email`) AS `fw`
ON `fw`.`user_email` LIKE `c`.`comment_author_email` WHERE
`c`.`comment_approved` = '1' GROUP BY `c`.`comment_author_email`,
`c`.`comment_author` ORDER BY `count` DESC LIMIT 7 OFFSET 0;

As you can see below, the two fields have different collation settings indeed:

so the message reflects what's in the tables.

I would say either enforce collation on the JOIN operator or update one of the tables (the latter one preferably) so that collations match.