Unbalanced brackets in JSON_OBJECTAGG upon HAVING with several conditions

CREATE TABLE t (f varchar(1));

INSERT INTO t VALUES ('a'),('b');

SELECT JSON_OBJECTAGG(f, f) AS ff FROM t HAVING (ff != 'foo' AND ff != 'bar');

MariaDB [test]> SELECT JSON_OBJECTAGG(f, f) AS ff FROM t HAVING (ff != 'foo' AND ff != 'bar');

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

| ff                   |

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

| {"a":"a", "b":"b"}}} |

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

1 row in set (0.002 sec)