SELECT MIN on Spider table returns more rows than expected

SET @@session.spider_same_server_link = ON;

GRANT ALL PRIVILEGES ON *.* TO 'spinne'@'127.0.0.1'  IDENTIFIED BY 'Widow2021!';

DROP SERVER data1;

CREATE SERVER IF NOT EXISTS data1

FOREIGN DATA WRAPPER mysql

OPTIONS(

HOST '127.0.0.1',

DATABASE 'test',

USER 'spinne',

PORT 3307,

PASSWORD 'Widow2021!'

);

DROP DATABASE IF EXISTS auto_test_local;

DROP DATABASE IF EXISTS auto_test_remote;

CREATE DATABASE auto_test_local;

USE auto_test_local;

CREATE TABLE IF NOT EXISTS `sp` (

  `c1` varchar(10) NOT NULL,

  `c2` varchar(17) NOT NULL,

  `c3` datetime NOT NULL DEFAULT '0001-01-01 00:00:00',

  PRIMARY KEY (`c1`,`c2`,`c3`)

) ENGINE=SPIDER DEFAULT CHARSET=utf8 COMMENT='wrapper "mariadb", table "sp"'

PARTITION BY LIST COLUMNS(`c2`)

(PARTITION `pt1` DEFAULT COMMENT = 'srv "data1"' ENGINE = SPIDER);

CREATE DATABASE auto_test_remote;

USE auto_test_remote;

CREATE TABLE IF NOT EXISTS `sp` (

  `c1` varchar(10) NOT NULL,

  `c2` varchar(17) NOT NULL,

  `c3` datetime NOT NULL DEFAULT '0001-01-01 00:00:00',

  PRIMARY KEY (`c1`,`c2`,`c3`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=8

 PARTITION BY RANGE  COLUMNS(`c3`)

(PARTITION `pmax` VALUES LESS THAN (MAXVALUE) ENGINE = InnoDB);

INSERT INTO auto_test_remote.sp VALUES

('00166','1','2020-05-05 00:00:00'),

('00166','2','2020-05-03 00:00:00'),

('00166','3','2020-05-02 00:00:00'),

('00166','4','2020-05-01 00:00:00'),

('00166','5','2020-05-06 00:00:00'),

('00174','6','2020-05-06 00:00:00'),

('00174','7','2020-05-06 00:00:00'),

('00174','8','2020-05-04 00:00:00');

SELECT MIN(c2),c1 FROM auto_test_local.sp WHERE c1='00166';

MariaDB > SELECT MIN(c2),c1 FROM auto_test_local.sp WHERE c1='00166';

+---------+-------+

| MIN(c2) | c1    |

+---------+-------+

| 1       | 00166 |

| 1       | 00166 |

| 1       | 00166 |

| 1       | 00166 |

| 1       | 00166 |

+---------+-------+

5 rows in set (0.042 sec)