It sounds like you and your customers are seeing an 'I agree with the terms and conditions' message on the cart, is that right? Which theme are you using?
I ask this because most themes won't have natively had this feature, and instead can be added on using a third-party app like theTerms and Conditions Checkboxor through theme customization. Do you know if you have any apps that could support this feature, or if you've made any customizations on your shop?
If you could please provide me with your shop's URL and a screenshot of where you're seeing this messaging, I'd be happy to see if I can replicate this on my end as well.
I'm also curious to learn where you've gathered that this 'terms and conditions' checkbox is the source of deterring your customers from your website. There could be a number of reasons that visitors leave a website. What are you seeing in your analytics that is driving you to that conclusion?