Adding a Common Hop Link URL does not override your landing page URLs for product-specific Hop Links. Your Common Hop Links will redirect to that URL, and your product-specific hop links will redirect to their own URLs. However, if you disable a product-specific hop link or delete the product, any hop links previously issued for that product would continue to function as if they were Common Hop Links, redirecting to your Common Hop Link URL as a fallback/default landing page.
Currently it appears your Common Hop Link is redirecting to your site's homepage, and your "6 weeks" products' hop links are both redirecting to some sort of list sign-up page (same page for both products), though the preorder version is granting a 0% commission. Whenever you enable a product-specific hop link, the product share % you enter there overrides your common share % on all affiliate-referred sales of that product, regardless of what kind of hop link the buyer followed. Your "meal planning" product currently does not have a product-specific hop link set up, so if you'd previously offered product-specific hop links for that item, those links would now be working as if they were Common Hop Links.