Athena ROW_Number order by doesnt works correctly

Hello, I’ve a problem with the ordering generated by row_number, I have two STRING type columns (str_dt,str_ts) I need to order the column generated by:

COALESCE(REPLACE(str_ts,", N ULL), str_dt) AS bigint

But the order of row_number doesn't seem to make sense with id= 1, especially at row_number=8

id str_dt str_ts Int_ts row_number 1 20240202 20240202105612 20240202105612 1 1 20240202 20240202115613 20240202115613 2 1 20240202 20240202125612 20240202125612 3 1 20240202 20240202135611 20240202135611 4 1 20240202 20240202170000 20240202170000 5 1 20240202 20240202170001 20240202170001 6 1 20240202 20240202170003 20240202170003 7 1 20240202 20240129165611 20240129165611 8 2 20231211 20231211 2 2 20231212 20231212 1

This is the query:

ROW_NUMBER() OVER(PARTITION BY id ORDER BY cast(COALESCE(REPLACE(str_ts,", N ULL), str_dt) AS bigint) DESC) AS row_n

This is the expected order:

20240202170003 20240202170001 20240202170000 20240202135611 20240202125612 20240202115613 20240202105612 20240129165611

I’ve noticed that with REPLACE(str_ts,", N ULL)AS bigint, without Coalesce works correctly Is there a problem with COALESCE?