Oracle database 12c : ORACLE JSON QUERY SEARCH - sql

Question

Creating two types of table to store JSON values (BLOB and NCLOB) and my aim to search the required values from JSON table;
Code Snippet 1: Creating table with one column as NCLOB.
create table departments_json_nclob (
department_id integer not null primary key,
department_data NCLOB not null
);
Simple insert with multibyte character (that is value : məharaːʂʈrə):
insert into departments_json_nclob
values ( 200,'{"department_list":[{"Deptname":"DEPT-A", "value" : "məharaːʂʈrə"}]}');
Code Snippet 2: Now, I have created one other table with BLOB datatype:
create table departments_json (
department_id integer not null primary key,
department_data blob not null
);
Added constraint to allow only JSON
alter table departments_json
add constraint dept_data_json
check ( department_data is JSON FORMAT JSON STRICT );
Insert normal JSON
insert into departments_json
values ( 100, utl_raw.cast_to_raw ('{"department_list":[{"Deptname":"DEPT-A", "value" : "məharaːʂʈrə"}]}'));
Insertion Verified from below query:
SELECT json_value(department_data format json, '$.department_list.value' )
FROM departments_json JS
WHERE DEPARTMENT_ID=100;
output is: məharaːʂʈrə
Now, I will have one more insertion in same table i.e. 'departments_json' but this time I will take required insertion value from NCLOB table departments_json_nclob:
declare
i nclob;
begin
select department_data into i from departments_json_nclob where department_id =200;
--inserting same way as I inserted in departments_json for department_id 100 but value comes from NCLOB
insert into departments_json
values ( 101, utl_raw.cast_to_raw (i));
commit;
end;
Again, insertion verified with below query:
SELECT json_value(department_data format json, '$.department_list.value' )
FROM departments_json JS
WHERE DEPARTMENT_ID=101;
output is: məharaːʂʈrə
Now my question is:
When I search for multibyte character, query return result of one query only that is direct insertion in BLOB table. Which is DEPARTMENT_ID=100 - why not 101?
Below query:
SELECT *
FROM departments_json
WHERE JSON_value(department_data format json, '$.department_list.value') = ('məharaːʂʈrə');
SELECT *
FROM departments_json
WHERE JSON_TEXTCONTAINS(department_data, '$.department_list.value', 'məharaːʂʈrə')
below query shows which character are multibyte:
select c, length(c), lengthb(c)
from ( select substr(s, level, 1) c
from ( select 'məharaːʂʈrə' s
from dual)
connect by level <= length(s));