Hello habibalex,
Thanks for your post.
See below from the help guide.
Note: If you inputted your own Offset value, it will be overwritten by values downloaded from the data server if it exists there. To prevent this you will need to ensure that your rollover date is not the same as the ones coming from the data server.
Below I have provided a link to the Understanding the Misc tab - Offset Value section of the help guide.
http://ninjatrader.com/support/helpG...nstruments.htm