 <p>It's a conflict of slugs. </p> <p>You will get conflicts if you have the same slug for a page and a CPT that uses that too. So for you, your CPT is using '<code>product</code>', and your page is too. That's conflicting and causing the 404. </p> <p>Rename your page <code>Product Info</code> page' slug to <code>product-info</code>. </p> <p><img src="https://i.stack.imgur.com/epnMh.png" alt="enter image description here"></p> <p>For safety purposes flush your permalink cache by setting them to Default, saving, then saving them as what you had previously. </p>