Hi,
To make the search really fast, I had to prepare custom AJAX endpoint in a special WordPress SHORTINIT mode. I noticed that some security plugins with specific settings can block access to this endpoint. Generally, it’s easy to fix. I work on better compatibility with security plugins.
I’m here to assist you. Go to WooCommerce -> AJAX search form -> click the link “contact” and send Technical Support request.
Because the thread is related to the pro version, I marked it as resolved. Just create Pro support ticket.
I wish you all the best and if you have any questions, do not hesitate to get in touch.
Best
Damian Góra