oracle 12c query is slow - oracle

Question

below code works well in 11g BUT only in 12c works so slow (over 10 sec).
SELECT * FROM DMProgValue_00001
WHERE 1=1
AND ProgressOID IN (
SELECT P.OID FROM (
SELECT OID FROM (
SELECT A.OID, ROWNUM as seqNum FROM (
SELECT OID FROM DMProgress_00001 WHERE 1=1
AND Project = 'Q539'
ORDER BY actCode
) A
WHERE ROWNUM <= 40
) WHERE seqNum > 20
) P
);
Plan hash value: 763232015
-----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 189 | 171 (1)| 00:00:01 |
|* 1 | FILTER | | | | | |
| 2 | TABLE ACCESS FULL | DMPROGVALUE_00001 | 1 | 189 | 68 (0)| 00:00:01 |
|* 3 | VIEW | | 20 | 800 | 103 (1)| 00:00:01 |
|* 4 | COUNT STOPKEY | | | | | |
| 5 | VIEW | | 2916 | 78732 | 103 (1)| 00:00:01 |
|* 6 | SORT ORDER BY STOPKEY| | 2916 | 130K| 103 (1)| 00:00:01 |
|* 7 | TABLE ACCESS FULL | DMPROGRESS_00001 | 2916 | 130K| 102 (0)| 00:00:01 |
-----------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter( EXISTS (SELECT 0 FROM (SELECT "A"."OID" "OID",ROWNUM "SEQNUM" FROM
(SELECT "OID" "OID" FROM "DMPROGRESS_00001" "DMPROGRESS_00001" WHERE
"PHASE"='Construction' AND "PROJECT"='Q539' ORDER BY "ACTCODE") "A" WHERE ROWNUM<=40)
"from$_subquery$_003" WHERE "SEQNUM">20 AND "OID"=:B1))
3 - filter("SEQNUM">20 AND "OID"=:B1)
4 - filter(ROWNUM<=40)
6 - filter(ROWNUM<=40)
7 - filter("PHASE"='Construction' AND "PROJECT"='Q539')
DMProgress_0001 stats
NUM_ROW : 10385
BLOCKS : 370
AVG_ROW_LEN : 176
SMAPLE_SIZE : 8263
DMProgvalue_0001 stats
NUM_ROW : 15703
BLOCKS : 244
AVG_ROW_LEN : 49
SMAPLE_SIZE : 5033
It's only 10k rows and Indexs are well made ( I can tell because of 11g experience). I know some detour way to make fast ( below code - 0.001 sec) BUT I want to know real problem and fix it.
I cannot understand it only has one sub query and 10k rows for each table. Not just compared to 11g, There is no way that this query takes over 10 sec.
SELECT * FROM DMProgValue_00001 V,
(SELECT OID FROM (
SELECT A.OID, ROWNUM as seqNum FROM (
SELECT OID FROM DMProgress_00001 WHERE 1=1
AND Project = 'Q539'
ORDER BY actCode
) A
WHERE ROWNUM <= 40
) WHERE seqNum > 20
) P
WHERE 1=1
AND V.ProgressOID = P.OID;
added 11g similar query plan
Plan hash value: 3049049852
-----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 9 | 684 | 49 (5)| 00:00:01 |
|* 1 | HASH JOIN RIGHT SEMI | | 9 | 684 | 49 (5)| 00:00:01 |
| 2 | VIEW | VW_NSO_1 | 3 | 81 | 35 (3)| 00:00:01 |
|* 3 | VIEW | | 3 | 75 | 35 (3)| 00:00:01 |
|* 4 | COUNT STOPKEY | | | | | |
| 5 | VIEW | | 3 | 36 | 35 (3)| 00:00:01 |
|* 6 | SORT ORDER BY STOPKEY| | 3 | 144 | 35 (3)| 00:00:01 |
|* 7 | TABLE ACCESS FULL | DMPROGRESS_00037 | 3 | 144 | 34 (0)| 00:00:01 |
| 8 | TABLE ACCESS FULL | DMPROGVALUE_00037 | 5106 | 244K| 13 (0)| 00:00:01 |
------------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - access("PROGRESSOID"="OID")
3 - filter("SEQNUM">20)
4 - filter(ROWNUM<=40)
6 - filter(ROWNUM<=40)
7 - filter("DISPLINE"='Q340' AND "PHASE"='Procurement' AND "PROJECT"='Moho')
oracle 11g automatically change the query as Hash join BUT 12c does not. I think this is point. They are same structure.