Cursor comparison not detecting duplicate rows

Describe the bug
When I compare two cursors using .join_by the duplicate rows are not detected (I'm attaching an example code).

Provide version info
Oracle Database 23ai Free Release 23.0.0.0.0
utPLSQL version: v3.1.14.4197
NLS: Polish
OS: x86_64/Linux 2.4.xx

Information about client software
Client: SQLDeveloper

To Reproduce
Steps to reproduce the behavior:

1. Prepare two identical cursors with a column you can join on.
2. Ensure one of the cursors has an additional row, identical to the ones already present.
3. Run ut.expect to compare them using .join_by(...).
4. See a message (via dbms_output) indicating a SUCCESS, yet clearly stating different rowcounts.

Expected behavior
The expectation should result in a FAILURE, not a SUCCESS. The rowcounts are clearly different, so the cursors don't yield the same rows, hence are not equal.

Example code

set serveroutput on
declare
  l_actual   sys_refcursor;
  l_expected sys_refcursor;
begin
  open l_expected for 
    select 'FOO'  username, 12 from dual union all
    select 'TEST' username, -600 user_id from dual
    order by 1 desc;
  open l_actual for 
    select 'FOO'  username, 12 from dual union all
    select 'TEST' username, -600 user_id from dual union all
    -- DUPLICATE!!!
    select 'TEST' username, -600 user_id from dual
    order by 1 asc;
  ut.expect( l_actual ).to_equal( l_expected ).join_by('USERNAME');
end;
/
--------
/* The result is:
SUCCESS
  Actual: refcursor [ count = 3 ] was expected to equal: refcursor [ count = 2 ]
*/