mariadb user defined aggregate function

I am using mariadb 10.3.9, and have created a user defined aggregate function (UDAF) and placed in a common_schema. This schema contains my utility functions to be used by other schema/databases on the same server.

The issue is that when calling the UDAF while using any other schema, it always return NULL!

The following is to demonstrate the issue:

CREATE SCHEMA IF NOT EXISTS common_schema;
DELIMITER $$
DROP FUNCTION IF EXISTS common_schema.add_ints $$
CREATE FUNCTION common_schema.add_ints(int_1 INT, int_2 INT) RETURNS INT NO SQL 
BEGIN 
    RETURN int_1 + int_2; 
END $$ 
DROP FUNCTION IF EXISTS common_schema.sum_ints $$
CREATE AGGREGATE FUNCTION common_schema.sum_ints(int_val INT) RETURNS INT 
BEGIN 
    DECLARE result INT DEFAULT 0; 
    DECLARE CONTINUE HANDLER FOR NOT FOUND RETURN result; 
    LOOP FETCH GROUP NEXT ROW; 
        SET result = common_schema.add_ints(result, int_val); 
    END LOOP; 
END $$

DELIMITER ; 
 

Now, calling it this way, returns the result as expected:

USE common_schema;
SELECT common_schema.sum_ints(seq)
FROM (SELECT 1 seq UNION ALL SELECT 2) t; 
-- result: 3
 

Calling it using any other schema, it returns NULL:

USE other_schema;
SELECT common_schema.sum_ints(seq) 
FROM (SELECT 1 seq UNION ALL SELECT 2) t; 
-- result: null
 

Am I missing something here? Is there any configuration that is missing?

Appreciate your help.