SQLSTATE[42000]: Syntax error or access violation: 1055 'x' isn't in GROUP BY

Edit config\database.php

Disable all strict modes:

'strict' => false,

Keep strict enabled, and disable only ONLY_FULL_GROUP_BY mode:

'mysql' => [
   'strict' => true,
   'modes' => [
        // 'ONLY_FULL_GROUP_BY',
        'STRICT_TRANS_TABLES',
        'NO_ZERO_IN_DATE',
        'NO_ZERO_DATE',
        'ERROR_FOR_DIVISION_BY_ZERO',
        'NO_AUTO_CREATE_USER',
        'NO_ENGINE_SUBSTITUTION'
    ],
]