Custom field for CartOrder and Order

Hi

 Trying to do a custom field in the checkout that is stored in the db.

Followed this docs.sitefinity.com/for-developers-persist-the-values-of-the-fields-in-the-cartorder-instance

I got the value to the CartOrder table, but it isn't transfered to the sf_ec_Order table. I thought this should be done by sitefinity, but maybe I need to hook up on some OnOrderPlaced event to transfer the field to sf_ec_order?