
By default, if you have Big plan or higher then the app uses its resources to import multiple items at the same time to best leverage import speed in Shopify because of this the app does not guarantee the order in which the items are imported.
Now you can select an option to force your items to be created in the same order as they are in the file you are importing, but since this will force to create Products one by one then the app will not use its full offered Enterprise or Big plan speed.
The most common use case for this would be when you are importing Products that will be added to the Collection which is sorted by the creation date. To make sure that Products are created in the correct order you can now select the option “Import items in the order as they appear in file (will not leverage the speed improvement)” in the Matrixify when importing a file.