Because of your password. You can see password validate configuration metrics using the following query in MySQL client:
SHOW VARIABLES LIKE 'validate_password%';
The output should be something like that :
+--------------------------------------+-------+ | 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 | +--------------------------------------+-------+
then you can set the password policy level lower, for example:
SET GLOBAL validate_password.length = 6; SET GLOBAL validate_password.number_count = 0;
Check the MySQL Documentation.