When you press the buy button, nothing happens and the side cart appears empty. The product even goes to the cart page, but only appears after reloading. I had to go back to the old mode of redirection for checkout.
Please always attach a link to your website so we can check it out. If the page is offline(localhost), then our help will be limited. You will have to contact us when the page is online. Also, please make sure that the page is not under maintenance before you provide us with the link.
It is always a good idea to also attach a screenshot showing your issue.