SELECT DISTINCT returns an incorrect number of rows when ORDER BY is used

create table mcs1(i bigint, i2 bigint)engine=columnstore;

insert into mcs1 values (1,2),(3,4),(3,5);

select disctinct i from mcs1;

MariaDB [test]> select distinct i from mcs1;

+------+

| i    |

+------+

|    1 |

|    3 |

+------+

2 rows in set (0.080 sec)

MariaDB [test]> select distinct i from mcs1 order by i2;

+------+

| i    |

+------+

|    1 |

|    3 |

|    3 |

+------+

3 rows in set (0.028 sec)