We are attempting to add order reconciliation functionality to a Drupal Commerce site: distributors can download orders placed for their products, they update in a CSV with status of those line items, then upload that CSV again to fill in the new information (fulfillment date, quantity fulfilled, etc) on the existing line items.
Unfortunately, Feeds doesn't seem to be able to update existing line items. I have the mapping set so the line item is my unique field, which means it should update when the line item ID matches (I've used Feeds a few times before and it always works well for that). If the settings allow for creating new items, it will make new ones with new line items rather than matching. If the settings are clear to only update existing items, it will say there is nothing new so doesn't do anything.
It is relying on a dev module Feeds Entity Processor, so it might be as simple as that module being buggy, or it might be something about how line items work which doesn't allow updating.
I appreciate any help that you can give, either along this approach or if you know of a completely different way.