cursor: mutex S wait

Hello,

The application running insert statement (using values) to big table with hundreds of columns from 5 different connections

and this cause conncurrency (cursor: mutex S wait). there are many child cursors (according to v$sql_shared_cursor)

for the insert sql_id (the reason is BIND_LENGTH_UPGRADEABLE)

Is there a way to decrease the wait event (cursor: mutex S wait) and improve performance?

cursor_sharing set to exact.

Version:  11.2.0.1.0

Many Thanks in Advance,

Galit.