Woocommerce checkout page is locked and cannot proceed to checkout

Recently, I am working on a foreign trade website of Wordpress+Woocommerce. It was about to end, and then I went on a trip for 2 days. I came back and continued to do it. At the checkout, I found that Woocommerce turned gray and white when it arrived at Review & Payment, and I couldn’t check out, as shown below, Viewing the CSS of the element appears blockUI.blockOverlay, which is locked. I checked a lot of information and tried to modify the CSS. Although it is not covered by gray and white, I still cannot click to checkout. Later, I saw the section about the Enfold theme and said to upgrade the theme to the latest version. Since I am using the Avada theme, it should be okay. There is really no other way. I checked Avada for a new version update, and it turned out that a new version came out. I updated it decisively and the problem disappeared.