Woocommerce Payment Gateway Not Showing ( BrainTree / Amazon )

Add this into the Custom CSS box located in your Salient Options panel (Make Sure there are no red cross in the Box) :

/* show any Iframe added by Payment Gateway as theme has inline style that hides the iframes by default */
.woocommerce-checkout iframe {
    opacity: 1 !important;
}
.woocommerce .payment_methods iframe {
    opacity: 1 !important;
}
.wc-braintree-hosted-field iframe {
    opacity: 1!important;
}