Why do we see 300+ entries in v$sql_shared_cursor reasons: Insert Direct Load mismatch for same SQL

Why are we seeing 300+ entries in v$sql_shared_cursor with reasons of:
"...Insert Direct Load mismatch(...)..." for the same SQL

Oracle Version : 12.1.0.2
(I believe this was an issue in 12.1.0.1 
Bug 9380377 - INSERT / MERGE child cursor leak due to INST_DRTLD_MISMATCH - superceded (Doc ID 9380377.8))

SQL:

MERGE INTO X LCT 

USING 

( SELECT LC.ROWID RID 

FROM Y LS 

INNER JOIN X LC ON LC.STRUCTUREID = LS.ID 

WHERE LS.MASTERID = :B1 ) SRC ON 

(LCT.ROWID = SRC.RID) 

WHEN MATCHED THEN 

UPDATE 

SET LCT.LOT = :B6, LCT.APPSOURCE = SUBSTR(TRIM(:B5 ), 0, 255), LCT.APPVERSION = SUBSTR(TRIM(:B4 ), 0, 30), LCT.UPDATEDBY = SUBSTR(TRIM(:B3 ), 0, 10), LCT.CLIENTDEVICE = SUBSTR(TRIM(:B2 ), 0, 30), LCT.UPDATEDON = SYSTIMESTAMP