It seems that the problem was identified!

The target (very first ) activity after the start takes a value from the Oracle DB.  This value was stored just after the process had been created. So looks like there is not enough time to store the value in the DB, before the query from the target activity comes.

As a solution a new intermediate activity with a placeholder was created. After the value is stored in the DB the process must be explicit pushed further to the target activity.