Wrong Auto Stats Collection after INSERT ON DUPLICATE

mysql [localhost:10417] {msandbox} (test) > select @@version ;

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

| @@version       |

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

| 10.4.17-MariaDB |

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

1 row in set (0.000 sec)

mysql [localhost:10417] {msandbox} (test) > CREATE TABLE `t1` (

    ->   `c1` int(10) unsigned NOT NULL DEFAULT 0,

    ->   `c2` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',

    ->   `c3` varchar(128) DEFAULT NULL,

    ->   `c4` char(1) DEFAULT NULL,

    ->   `c5` tinyint(3) unsigned DEFAULT NULL,

    ->   UNIQUE KEY `uniq` (`c1`,`c3`),

    ->   KEY `c3` (`c3`),

    ->   KEY `c2` (`c2`)

    -> ) ENGINE=InnoDB DEFAULT CHARSET=latin1 ;

Query OK, 0 rows affected (0.010 sec)

mysql [localhost:10417] {msandbox} (test) > source test_case.sql

Query OK, 0 rows affected (0.003 sec)

...

mysql [localhost:10417] {msandbox} (test) > show table status like 't1'\G

*************************** 1. row ***************************

            Name: t1

          Engine: InnoDB

         Version: 10

      Row_format: Dynamic

            Rows: 0

  Avg_row_length: 0

     Data_length: 16384

 Max_data_length: 0

    Index_length: 49152

       Data_free: 0

  Auto_increment: NULL

     Create_time: 2020-11-18 17:17:41

     Update_time: 2020-11-18 17:17:53

      Check_time: NULL

       Collation: latin1_swedish_ci

        Checksum: NULL

  Create_options: 

         Comment: 

Max_index_length: 0

       Temporary: N

1 row in set (0.001 sec)

mysql [localhost:10417] {msandbox} (test) > show indexes from t1 ;

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

| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |

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

| t1    |          0 | uniq     |            1 | c1          | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |

| t1    |          0 | uniq     |            2 | c3          | A         |           0 |     NULL | NULL   | YES  | BTREE      |         |               |

| t1    |          1 | c3       |            1 | c3          | A         |           0 |     NULL | NULL   | YES  | BTREE      |         |               |

| t1    |          1 | c2       |            1 | c2          | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |

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

4 rows in set (0.001 sec)