SQLERRD(2) not accurate for SQL with CTE and HAVING clause

Hello,

After I open an insensitive cursor, according to IBM documentation:
"SQLERRD(2) contains the actual number of rows in the result set." However,
this does not seem to be working for my SQL which has a CTE and a HAVING
clause. I simplified my example to make it as generic as possible:

**FREE

DCL-S NumRows INT(10);

EXEC SQL DECLARE TESTCSR INSENSITIVE CURSOR FOR
WITH IDs (ID) AS (
SELECT Identity FROM TABLET
)
SELECT ID
FROM IDs
GROUP BY ID
HAVING COUNT(*) > 1;

EXEC SQL OPEN TESTCSR;

NumRows = SQLERRD(2);

EXEC SQL CLOSE TESTCSR;

*INLR = *ON;
RETURN;

Assuming "Identity" is unique in TABLET, this SQL should always have 0
results and I would expect NumRows to get set to 0. However, it seems to be
getting set to the number of records in TABLET instead.

Is this a bug or is this an intended case where SQLERRD(2) is an estimate
instead of a real number of rows?

Thank you