WooCommerce bookings calendar slow to load

I am having issues with the WooCommerce Bookings calendar being extremely slow to load, with the calendar not loading but just ‘spinning’ and so customers can’t choose a date to book. I have switched off rocket loader, and have done a page rule to bypass *product but the issues persist. I have been recommended to exclude woocommerce from cache, but I don’t know if that is covered by the page rule. This issue has persisted for months, and seems to be getting slower. Any advice gratefully received!