MySql password and old_password

/* Old password type */
SET PASSWORD FOR 'some_user'@'some_host' = OLD_PASSWORD('mypass');
/* New password type */
SET PASSWORD FOR 'some_user'@'some_host' = PASSWORD('mypass');
 
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password  BY 'mypass';

SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+-------+
| Variable_name                        | Value |
+--------------------------------------+-------+
| validate_password.check_user_name    | ON    |
| validate_password.dictionary_file    |       |
| validate_password.length             | 6     |
| validate_password.mixed_case_count   | 1     |
| validate_password.number_count       | 1     |
| validate_password.policy             | LOW   |
| validate_password.special_char_count | 1     |
+--------------------------------------+-------+
SET GLOBAL validate_password.length = 6;
SET GLOBAL validate_password.number_count = 0;