Theme interferes with WooCommerce Checkout

Hi. I need your help. I have already gotten help from WooCommerce and we have identified that the checkout returns no issues with any other themes, just not this one. it was working fine a few days ago. But now, when you add things to the cart and try to check out, there is no checkout option. You can imagine that I need this resolved asap as this is how my customers sign up and make purchases.