If you've successfully transferred products from Shopify to Etsy using Shuttle (with no errors reported) but still can't locate them, they are likely in your Drafts section on Etsy.
Shuttle transfers products to Etsy as drafts to help you avoid unnecessary Etsy listing fees. Once transferred, you can selectively activate only the products you need to list publicly, ensuring you only incur fees for items you actively sell.
How to find your transferred products:
Log in to your Etsy account
Navigate to Shop Manager → Listings → Drafts
Activate the products you wish to list publicly