FGA - Bind variables not replaced by their values in _FGA_AUDIT_TRAIL

Hello,

Context: DB 11gR2 (11.2.0.3) and EBS R12.1.3

I have created a policy for the table applsys.FND_CONCURRENT_TIME_PERIODS with the parameter "audit_trail => DBMS_FGA.DB + DBMS_FGA.EXTENDED".

When i execute the following request (SQL*PLUS, TOAD):

update FND_CONCURRENT_TIME_PERIODS set START_TIME=:1 where CONCURRENT_TIME_PERIOD_NAME='<one name>';

The value given to the bind variable is not registered in the column SQL_TEXT of the table DBA_FGA_AUDIT_TRAIL (appears 1:).

Same remark when updating the field Start_time in EBS (Resp. System Administrator).

I'm surprised because of DBMS_FGA.EXTENDED.