Why do goods on the site disappear when unloading from 1C?

Question

1C-Bitrix

Good afternoon, there was a problem when exchanging data between Bitrix and 1C. After unloading goods from 1C to the site, only those goods that have been changed on the 1C side remain in the infoblock of the product catalog, and the goods that have not been changed on the 1C side disappear from the infoblock altogether. What could be the reason? What parameter should be specified in the exchange XML file so that Bitrix does not delete those products on the site that have not been changed on the 1C side?

Answer 1

This behavior is possible with full unloading, discard the screen of the 1C exchange module settings.