1) Point is that if we enabled the default WooCommerce theme Storefront and checked it also does not work https://gyazo.com/102141396092155c54b653364ac7f7fd Storefront is the official theme of the WooCommerce team.
3) It does not display sale price even with the Storefront http://prntscr.com/ru6se1 Contact plugin author.
I suppose something is wrong with your products and all these things, including Ajax filter does not work because of this but we can’t help you if default WooCommerce functions do not work with the default WooCommerce theme. Solve these issues and then if you still have problem with the Ajax filter contact us again.
