The Woocommerce Upload Files plugin is adding this CSS:
/* Drag & Drop won't work otherwise */
.cart-collaterals {
pointer-events: none;
}
.woocommerce-cart .cart-collaterals .cart_totals table, .wc-proceed-to-checkout, .woocommerce .cart_totals, .checkout_coupon, .cart-update-buttons,
.checkout-button, .cart-collaterals button, .cart-collaterals input, .cart_totals input, #shipping_method input
{
pointer-events: all;
}
/* */
Which disables the pointer events on all Pages then re-enables them on the Cart and Checkout…. However your cart page is not the default Woo cart page so it remains disabled.
You can use this CSS to target your custom cart page and fix the issue:
.page-id-3352 .cart-collaterals {
pointer-events: all;
}