Misconfigured canonical tag
What it means
Internal pages point to the homepage as canonical. Google treats them as duplicates and may not index them separately.
Why it happens on Shopify
In a React or Vite SPA, the canonical is often hardcoded in index.html to the homepage instead of being route-specific.
On native Shopify, themes usually output canonicals, but collection-scoped product URLs can be wrong if the theme is misconfigured.