SELECT FOR UPDATE returns zero rows with CTE

Why does SELECT FOR UPDATE return 0 rows in the scenario below? (execution in transaction)

If delete 'FOR UPDATE', 1 row returnedTest case:

DROP TABLE IF EXISTS t1;
DROP TABLE IF EXISTS t2;
CREATE TABLE t1 (_pk serial, t1c1 integer, t1c2 integer, t1c3 text);
CREATE TABLE t2 (_pk serial, t2c1 text, t2c2 integer);
insert into t1 (t1c1, t1c2, t1c3) values(123456789, 100, 'string_value_1');
insert into t2 (t2c1, t2c2) values('string_value_2', 100);


WITH    cte1 AS (        UPDATE t1
SET t1c3 = 'string_value_1'
WHERE t1c1 = 123456789
returning t1c1, t1c2    ),    cte2 AS (        SELECT * FROM t1        WHERE             t1c1 = 123456789            AND t1c2 = (SELECT t1c2 FROM cte1)        FOR UPDATE    )

SELECT * FROM cte2;