Comments - JSON_ARRAYAGG

I have a query example:

with t1 as ( select 0 as a ) select JSON_ARRAYAGG(a) as j from t1 where a > 0

Docs tells j should be NULL Actually j is a string "[NULL]"

Can be connected with this: https://stackoverflow.com/questions/69872120/json-object-inside-json-arrayagg-sometimes-return-json-array-sometimes-string

I see NULL:

MariaDB [(none)]> with t1 as ( select 0 as a ) select version(), JSON_ARRAYAGG(a) as j from t1 where a > 0;
+----------------+------+
| version()      | j    |
+----------------+------+
| 10.6.5-MariaDB | NULL |
+----------------+------+
1 row in set (0.001 sec)