Added a Cart Attribute but can't proceed to checkout

Hi,

I wanted to add a Sales Rep input field in the Cart Page, so I followed this tutorial for sectioned themes.

When I added the code , I can see the cart attribute/input field in my cart page . However when I put some text in the field, I can’t proceed to the checkout page. Does anyone have any idea why this happens?

I can proceed to checkout if I leave the field blank. The form in the cart page also has the ‘novalidate’ since the field is not required.

thank you