Currently, Shopify prevents adding @app block types within sections that contain multiple link_list settings. This issue arises due to a restriction in Shopify’s theme architecture, where sections that support app blocks can only include one resource setting of each type in the section settings.
This means that if your section’s schema JSON includes more than one link_list, attempting to add an @app block will trigger an error and prevent the file from being uploaded. However, if you remove one of the link_list settings, Shopify will allow app blocks without any issues.
This behavior appears to be intentional to avoid conflicts with autofill settings, but it imposes an unnecessary limitation on theme customization and app integration.
If you need to use multiple link_list settings and app blocks within the same section, it is not possible.
Moreover, not allowing the use of app blocks due to this restriction creates unnecessary limitations for app developers relying on app blocks for seamless theme integrations.
This issue was closed by Shopify due to inactivity without providing a resolution, despite ongoing reports from developers. GitHub issue: [Bug/Featured]: Invalid schema: setting link_list type can only be inserted once in the settings · Issue #1965 · Shopify/cli · GitHub