I’ve built a demo Checkout UI extension (scaffolded via Shopify CLI) and it renders perfectly in dev preview (shopify app dev → Dev Console → preview link with ?dev=...). I’ve tried in‑checkout static targets like purchase.checkout.payment-method-list.render-before and a Thank you target like purchase.thank-you.footer.render-after. In both cases, the extension shows exactly where I expect in dev preview.
However, after running shopify app deploy and doing a normal checkout (no ?dev) on my dev store, the extension never appears—neither on the checkout steps nor on the Thank you page. I’ve moved to a fresh Plus dev store with Checkout Extensibility enabled, confirmed the app is installed on that store, and verified that shopify app info points to that same Plus dev store. Deploys succeed without errors, but the deployed version of the extension seems invisible in live checkout.
Has anyone seen this pattern before?
