A template can exist in a draft theme without appearing in a product’s Theme template dropdown. Shopify lists templates from the published theme.
Check the two theme names
Open Online Store → Themes and identify the published theme.
Open the editor where you can see your Sternify page.
Compare the theme names and note the exact product template name.
Read the badge beside the theme name in the editor header. Draft means this is not the published theme; its product templates will not populate the live product’s Theme template dropdown. Compare theme names before reinstalling or publishing anything.
If the names differ, you are editing a draft. You can keep working there without switching the storefront.
Keep building the draft
Finish the page and the rest of the theme. When the entire theme is ready, publish it and assign the finished template to your products.
Publishing changes the whole storefront theme. Do not publish an unfinished theme just to make one template appear.
Keep your current published theme
Choose that theme in Sternify’s installer and review any live-theme or replacement warning. Open the installed copy and check it before assigning products.
Your edits in the draft’s Shopify editor are not transferred by installing the original page again.
Already in the published theme?
Confirm it is a product template and check its exact name.
Reopen the product after installation has finished.
Select the template in the product’s Theme template field and save.
If it is still missing, send support the theme name, template name, and screenshots of the editor and dropdown.
Next: Edit and assign the page. See also Shopify’s template guide.