I’m sorry to hear you are having trouble with the Printful app integration on your store. Since the app is a third party integration, please reach out to the app developers directly to have the issue resolved. They’ll be able to take a closer look at how it is interacting with your store, and fix any issues that are causing it to not connect to your products properly.
You can easily contact them via email by going to Apps from your Shopify admin, and clicking on ‘Get Support’, as seen below:
Alternatively, if you click directly into the app itself, there is also a live chat option on the bottom right hand side of the screen. It looks like this:
Hope you find this information useful. All the best!
Helen | Social Care @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog