Select query succeeds however Insert using same query fails with ORA-00979 (not a GROUP BY expression)

Question

I am having a hard time finding why the below insert would fail while the select alone executes successfully.

INSERT INTO I6_POC_ADJ_OUTPUT
(LOADID,ADJ_ID,ADJ_CATEGORY,ADJ_COMMENT,ITEM,CHANNEL,FDATE,ADJ_TOT_QTY,FQTY)
SELECT 
    ADJ.LOADID,ADJ.ADJ_ID,ADJ.ADJ_CATEGORY,ADJ.ADJ_COMMENT,ADJ.ITEM,ADJ.CHANNEL,ADJ.FDATE,MAX(ADJ.FQTY) ADJ_TOT_QTY,
    SUM(ADJ.TP_SPLIT) FQTY
FROM I3_POC_ADJ_INPUT  ADJ,V_POC_HIST_BASE BASE
WHERE ADJ.ITEM=BASE.ITEM(+) AND ADJ.CHANNEL=BASE.CHANNEL(+) AND ADJ.FDATE=BASE.FDATE(+) 
AND ADJ.LOADID=71 AND ADJ.ITEM='10-56-034' AND ADJ.CHANNEL='CH1820' AND ADJ.FDATE=DATE'2017-09-03'
GROUP BY ADJ.LOADID,ADJ.ADJ_ID,ADJ.ADJ_CATEGORY,ADJ.ADJ_COMMENT,ADJ.ITEM,ADJ.CHANNEL,ADJ.FDATE;

Select and Insert Executions

Update:

Tried with a simple CTAS and it works.

CREATE TABLE TEST_ADJ_OUTPUT AS
SELECT * FROM (
 SELECT 
 ADJ.LOADID,ADJ.ADJ_ID,ADJ.ADJ_CATEGORY,ADJ.ADJ_COMMENT,ADJ.ITEM,ADJ.CHANNEL,ADJ.FDATE,MAX(ADJ.FQTY),
 SUM(ADJ.FQTY*ADJ.TP_SPLIT)
 FROM I3_POC_ADJ_INPUT  ADJ,V_POC_HIST_BASE BASE
 WHERE ADJ.ITEM=BASE.ITEM(+) AND ADJ.CHANNEL=BASE.CHANNEL(+) AND ADJ.FDATE=BASE.FDATE(+) 
 AND ADJ.LOADID=71 AND ADJ.ITEM='10-56-034' AND ADJ.CHANNEL='CH1820' AND ADJ.FDATE=DATE'2017-09-03'
 GROUP BY ADJ.LOADID,ADJ.ADJ_ID,ADJ.ADJ_CATEGORY,ADJ.ADJ_COMMENT,ADJ.ITEM,ADJ.CHANNEL,ADJ.FDATE
);

Truncated the same table and tried inserting into the same but if fails with the same error. "SQL Error: ORA-00979: not a GROUP BY expression"

TRUNCATE TABLE TEST_ADJ_OUTPUT;
INSERT INTO TEST_ADJ_OUTPUT
SELECT * FROM (
 SELECT 
 ADJ.LOADID,ADJ.ADJ_ID,ADJ.ADJ_CATEGORY,ADJ.ADJ_COMMENT,ADJ.ITEM,ADJ.CHANNEL,ADJ.FDATE,MAX(ADJ.FQTY),
 SUM(ADJ.FQTY*ADJ.TP_SPLIT)
 FROM I3_POC_ADJ_INPUT  ADJ,V_POC_HIST_BASE BASE
 WHERE ADJ.ITEM=BASE.ITEM(+) AND ADJ.CHANNEL=BASE.CHANNEL(+) AND ADJ.FDATE=BASE.FDATE(+) 
 AND ADJ.LOADID=71 AND ADJ.ITEM='10-56-034' AND ADJ.CHANNEL='CH1820' AND ADJ.FDATE=DATE'2017-09-03'
 GROUP BY ADJ.LOADID,ADJ.ADJ_ID,ADJ.ADJ_CATEGORY,ADJ.ADJ_COMMENT,ADJ.ITEM,ADJ.CHANNEL,ADJ.FDATE
);

Appreciate your help.

Thanks, Manoj