Hi, since the last update of your theme, the official Wooocommerce Waitlist no longer works. The button to apply for the waitlist doesn’t show on the product page, however it works with products that have variations. If I change to a default theme it works, so it’s something in your theme.
I already contacted with the plugin authors and they told to contact with you.
Site URL: hidden Theme version: Woopress 188.8.131.52 WooCommerce version: 3.0.9