How to fix my SQL Group By issue?
By default, Drupal use "Full_ group_by" so that why you need to Group all your fields.

If you want disable it and group only on one field, you have to update setting.php 

Add this : 

$databases['default']['default'] ['init_commands'] = [
'sql_mode' =&gt; "SET sql_mode = 'STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER'",
];