Some apps allow to create a bundle of products to show on the store. They are:
Product Bundle
Upsell
Cross-sell
Buy X Get Y
Related Products
If some products in a bundle aren’t showing up, it’s likely because the missing products are not set to be visible on the storefront.
Go to BigCommerce Admin and make sure they are visible on the current storefront.
If you need more help, feel free to contact Crucials Support for assistance.