When running Auto Maintenance AR_AUTOMNT App Engine, I get an error [Cannot insert the value NULL in

The App Engine AR_AUTOMNT, fails on the following SQL

UPDATE PS_MT_ITEM_TAO4 SET WORKSHEET_FLG = 'N'

(

SELECT T.WORKSHEET_FLG FROM PS_MT_TOTAL_TAO4 T

WHERE T.PROCESS_INSTANCE = 415295

AND T.CORPORATE_SETID = PS_MT_ITEM_TAO4.CORPORATE_SETID

AND T.CORPORATE_CUST_ID = PS_MT_ITEM_TAO4.CORPORATE_CUST_ID

AND T.MATCH_GROUP_ID = PS_MT_ITEM_TAO4.MATCH_GROUP_ID

)

WHERE PROCESS_INSTANCE = 415295

This is due to the PS_MT_TOTAL_TAO4 not having all the MATCHING_GROUP_IDs. Leaving the PS_MT_ITEM_TAO4.WORKSHEET_FLG  set NULL values for non-matching MATCHING_GROUP_IDs.