after changing SUM(tbk63.col_3) to -SUM(-tbk63.col_3) the col_2's value unexpectedly changes

mysql> WITH cte_387 AS (SELECT (SELECT s434.c5 AS subq_col FROM t1 AS s434 ORDER BY s434.c5 ASC LIMIT 1) AS col_3, STDDEV_POP(lrq50.c1) AS col_4 FROM t1 AS lrq50), cte_721 AS (SELECT (SELECT s258.c3 AS subq_col FROM t3 AS s258 ORDER BY s258.c3 ASC LIMIT 1) AS col_3 FROM t3 AS ack3) SELECT SUM(tbk63.col_3) AS col_2, CAST(tbk63.col_3 / 59 AS SIGNED) AS col_3 FROM cte_721 AS tbk63 GROUP BY CAST(tbk63.col_3 / 59 AS SIGNED) UNION ALL SELECT iha53.col_3 AS col_2, iha53.col_3 AS col_3 FROM cte_387 AS iha53;

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

| col_2                  | col_3      |

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

| 0x37393233             | 134        |

| 0x323032352D31302D3331 | 2025-10-31 |

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

2 rows in set (0.00 sec)

mysql> WITH cte_387 AS (SELECT (SELECT s434.c5 AS subq_col FROM t1 AS s434 ORDER BY s434.c5 ASC LIMIT 1) AS col_3, STDDEV_POP(lrq50.c1) AS col_4 FROM t1 AS lrq50), cte_721 AS (SELECT (SELECT s258.c3 AS subq_col FROM t3 AS s258 ORDER BY s258.c3 ASC LIMIT 1) AS col_3 FROM t3 AS ack3) SELECT -SUM(-tbk63.col_3) AS col_2, CAST(tbk63.col_3 / 59 AS SIGNED) AS col_3 FROM cte_721 AS tbk63 GROUP BY CAST(tbk63.col_3 / 59 AS SIGNED) UNION ALL SELECT iha53.col_3 AS col_2, iha53.col_3 AS col_3 FROM cte_387 AS iha53;

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

| col_2      | col_3      |

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

| 7923       | 134        |

| 2025-10-31 | 2025-10-31 |

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

2 rows in set (0.00 sec)

DROP DATABASE IF EXISTS test;

CREATE DATABASE IF NOT EXISTS test;

SET GLOBAL sort_buffer_size = 64 * 1024 * 1024;

SET GLOBAL read_rnd_buffer_size = 8 * 1024 * 1024;

USE test;

CREATE TABLE t1 (

    c1 INT NOT NULL AUTO_INCREMENT,

    c2 VARCHAR(255) NOT NULL,

    c3 VARCHAR(255) NULL,

    c4 INT NULL,

    c5 DATE NOT NULL,

    c6 VARCHAR(10) NOT NULL,

    PRIMARY KEY (c1)

);

CREATE TABLE t3 (

    c1 INT NOT NULL AUTO_INCREMENT,

    c2 INT NOT NULL,

    c3 INT NOT NULL,

    c4 YEAR NOT NULL,

    c5 DATETIME NULL,

    c6 TINYINT NULL,

    c7 SMALLINT NULL,

    c8 MEDIUMINT NULL,

    c9 BIGINT NULL,

    c10 LONGTEXT NULL,

    c11 GEOMETRY NULL,

    c12 TINYTEXT NULL,

    c13 TINYBLOB NULL,

    c14 SET('x','y','z') NULL,

    c15 TINYINT(1) NULL,

    PRIMARY KEY (c1)

);

INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (1536, 'sample_GnY9n2QDV85qyHNJTDLrOJTPlIQ8oGxJimWfYOsEh6behbazn3qFWLWwZZsbxWQEyMnsnutN5yfm3twOXszfJ8wc7cGulFFLkCJnGAyz2q3KFBkHgi', 'sample_mpQ8QD4GfiYD4nC1iUqox16013d5wRliF5oBHe8JA54FsT1uxuT8tGMkjdPdO4flcJdxSaERUZGMsKQooraoLUeKjvdU0kz8lCcYWgWwFuN2UOilVKapxKf5srFx9uDJYs55NxNomluPlyynCP7oeNXWS6HXUACuKgkAL3ww5OFzuTuY76XVGFDHViVUAhRCKRTGheCwHfwkD90Gsa6ZPcxJK4vZJkqCqtoTLmF4OoY0glRObF64Bakz', 74, '2025-10-31', 'sample_7b');

INSERT INTO t3 (c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11, c12, c13, c14, c15) VALUES (9473, 3166, 7923, 2009, '2025-10-28 00:33:04', 64, 33, 23, 5, 'sample_zTTcDyJQiepslGYJ3zx7HK7FrfiC27HYfiM2DyjEqVaxZXyJQZAk243c5b7yltsU3bDVzF2sv1hGOpsKD5u5Vsxz394dHEEgy83H8xb47ex2oB6Sq0o7pOfwoVHbKZu6RgdQZDvfErgKcrI6jjhxlh5vvf4A5bMHspZVCHf6xQTLobsltrxVRPWcVEpcFa5j1I95z3Z4Rjv7rhDXeACav9XF6AozF9GisKKaR6TZV1uqxe9tbHTweWshIEX8yNnrU3IxQZKPJKdvzuZULMFQtInIhk96d8YG30AdQ5pBtYaX65GusSaJXGMp3Ihk3IErQfBpVTu29NJzaMcfVkaVMp2xAwfBSI3cvVabVv8biqnHJEPV5TWpfuyEyNERmQB3uT4QchyRMQMwZvjD7dLdhzAswCYPfR1cgVswYIJ1uRUY5JmnVxXSazO9HaCdk42BhmyWoXGzKbcNQ4D5uw3C9jIuse73AKzFL2LkIeEwgZAsimZuiM7Q4EwQWxy7B09PFzXlmKpILqGuT0hKw5wsTyKNl0wjI2FNH2bPoVq4ujSAQDwJr4jSz38', ST_GeomFromText('POINT(-7.208789 -111.046928)'), 'sample_lo1SDGmMjznqDAbPH7lv1PLIycmmGnug3w9c1EMVaOOvVY0FM7GLWSZHVE6MVSrkzdR1XlrSer0Ae6U0ldCAgDDUG', X'CBBA34E99F8CDA95E4A2AFDF8210', 'z', NULL);

WITH cte_387 AS (SELECT (SELECT s434.c5 AS subq_col FROM t1 AS s434 ORDER BY s434.c5 ASC LIMIT 1) AS col_3, STDDEV_POP(lrq50.c1) AS col_4 FROM t1 AS lrq50), cte_721 AS (SELECT (SELECT s258.c3 AS subq_col FROM t3 AS s258 ORDER BY s258.c3 ASC LIMIT 1) AS col_3 FROM t3 AS ack3) SELECT SUM(tbk63.col_3) AS col_2, CAST(tbk63.col_3 / 59 AS SIGNED) AS col_3 FROM cte_721 AS tbk63 GROUP BY CAST(tbk63.col_3 / 59 AS SIGNED) UNION ALL SELECT iha53.col_3 AS col_2, iha53.col_3 AS col_3 FROM cte_387 AS iha53;

WITH cte_387 AS (SELECT (SELECT s434.c5 AS subq_col FROM t1 AS s434 ORDER BY s434.c5 ASC LIMIT 1) AS col_3, STDDEV_POP(lrq50.c1) AS col_4 FROM t1 AS lrq50), cte_721 AS (SELECT (SELECT s258.c3 AS subq_col FROM t3 AS s258 ORDER BY s258.c3 ASC LIMIT 1) AS col_3 FROM t3 AS ack3) SELECT -SUM(-tbk63.col_3) AS col_2, CAST(tbk63.col_3 / 59 AS SIGNED) AS col_3 FROM cte_721 AS tbk63 GROUP BY CAST(tbk63.col_3 / 59 AS SIGNED) UNION ALL SELECT iha53.col_3 AS col_2, iha53.col_3 AS col_3 FROM cte_387 AS iha53;