Blocked payment processing on WooCommerce site

Hi there, my client is using your hosting, the domain is no++++s.com. They have woocommerce set up with authorize.net.
Most orders going through fails and gives an error 403: forbidden. I was wondering if there are security preferences set up that may be rejecting order requests.
I saw on a forum that there may be something called Mod_security blocking certain requests. Not sure if it’s that or something else.