using the onpage load trigger wont work because the form has not posted yest.
the insert behavior is expecting to get data from the form post.
moving the insert to be after the form does not mean that the form has been posted.
to do this in a cron job, you cant rely on the post data.
where are the form elements getting the values?
A recordset?
if this is the case, create a single insert behavior that uses the recordset values, and add a loop so it will loop through the recordsset instead of using the form.