iOS 18 webView go back from systemB window.WebViewJavascriptBridge is undefine

[AkaShark]

I find that JS run the code

 if (this.deviceType() === DeviceType.IOS) {
            if (window.WebViewJavascriptBridge) {
                return callback(window.WebViewJavascriptBridge);
            }
            if (window.WVJBCallbacks) {
                return window.WVJBCallbacks.push(callback);
            }
            window.WVJBCallbacks = [callback];
            var WVJBIframe = document.createElement("iframe");
            WVJBIframe.style.display = "none";
            WVJBIframe.src = "https://__bridge_loaded__";
            document.documentElement.appendChild(WVJBIframe);
            setTimeout(function () {
                document.documentElement.removeChild(WVJBIframe);
            }, 0);
        }

In iOS 18, the intercepted URL is about: blank, whereas in iOS 17 it is __bridge__load__. I'm not familiar with it why

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    if (webView != _webView) { return; }
    NSURL *url = navigationAction.request.URL;
    __strong typeof(_webViewDelegate) strongDelegate = _webViewDelegate;

    if ([_base isWebViewJavascriptBridgeURL:url]) {
        if ([_base isBridgeLoadedURL:url]) {
            [_base injectJavascriptFile];
        } else if ([_base isQueueMessageURL:url]) {
            [self WKFlushMessageQueue];
        } else {
            [_base logUnkownMessage:url];
        }
        decisionHandler(WKNavigationActionPolicyCancel);
        return;
    }