Contact Form 7 causing issues with WooCommerce

While Contact Form 7 is activated on my clients site, https://www.freshforyou.ca, the “returning customer” link, on the Checkout page, doesn’t work.

I have both WooCommerce and Contact Form 7 operating on other client websites (also Genesis, with the same child theme), with no issues, so I don’t understand what the problem is with this site. The only difference with this site compared to the others, is that it uses PayPal Payments Pro to be able to accept cc on the site. I tried deactivating Payments Pro addon plugin while activating CF7, but still had the same problem, so assumed that it wasn’t as a result of the Payments Pro addon.

Any suggestions?