Javascript overlay redirect not displaying properly on Android WebView

Question

I am trying to implement a custom browser based on WebView. It works great on most websites, but on https://smittenkitchen.com/ I maybe missing something critical:

It loads and displays the homepage fine, but when typing a search term (e.g. "carrot"), it first lands on an ugly looking "search form" page, then it displays a blank overlay! (no trace of that overlay display/redirect in Logcat!)

On any standard web browser it first lands on that ugly looking "search form" page, then after 0.5-2 seconds it displays an overlay with the search results gradually being populated.

I am trying to understand what I am missing in my implementation:

In MyWebViewClient, I override:

• onPageStarted
• onPageFinished
• shouldOverrideUrlLoading
• onPageCommitVisible

However, the first 3 methods (onPageStarted, onPageFinished, shouldOverrideUrlLoading) only log a Logcat message when called, they do not do anything custom.

The only overridden method that does something custom (onPageCommitVisible) is only calling WebView's loadUrl() with:

javascript:window.HTMLOUT.processHTML(document.getElementsByTagName('html')[0].innerHTML)

facilitated by:

webView.addJavascriptInterface(new MyJavascriptInterface(this, webView), "HTMLOUT");

Note that shouldOverrideUrlLoading is never called by the Android WebView framework, despite the apparent redirect (perhaps because it is a client-side redirect, not changing the URL?)

@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
    Log.d("", "url: " + url + ", view: " + view.getUrl());
}
@Override
public void onPageFinished(WebView view, String url) {
    Log.d("", "url: " + url + ", view: " + view.getUrl());
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest webResourceRequest) {
    Log.d("", "webResourceRequest: " + webResourceRequest.getUrl() + ", view: " + view.getUrl());
    return false;
}
@Override
public void onPageCommitVisible(WebView view, String url) {
    super.onPageCommitVisible(view, url);
    view.loadUrl("javascript:window.HTMLOUT.processHTML(document.getElementsByTagName('html')[0].innerHTML)"); // convert all javascript to HTML
    Log.v("", "url (passed): " + url + " < view.getUrl(): " + view.getUrl());
}

Javascript is of course enabled:

webSettings.setJavaScriptEnabled(true);
webSettings.setSupportZoom(false);
webSettings.setBlockNetworkLoads(false);
webSettings.setDomStorageEnabled(true);

webSettings.setLoadWithOverviewMode(true);
webSettings.setUseWideViewPort(false);
webSettings.setBuiltInZoomControls(true);
webSettings.setDisplayZoomControls(false);
webSettings.setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);
webSettings.setCacheMode(WebSettings.LOAD_DEFAULT);

The relevant Logcat snippet is as follows:

11:12:03.716                           D   url: https://smittenkitchen.com/, view: https://smittenkitchen.com/ (called from: MyWebViewClient.onPageFinished) 
11:12:03.988                           D   url: https://smittenkitchen.com/, view: https://smittenkitchen.com/ (called from: MyWebViewClient.onPageStarted)
11:12:05.646                           E   net::ERR_CONNECTION_REFUSED(-6) on request: https://ssc.33across.com/api/v1/hb?guid=cYCh20L9Or64olaKj0P0Le, https://smittenkitchen.com/ (called from: MyWebViewClient.onReceivedError)
11:12:05.787  MyWebView                V   javascript:window.HTMLOUT.processHTML(document.getElementsByTagName('html')[0].innerHTML); (called from: MyWebView.loadUrl < MyWebViewClient.onPageCommitVisible)
11:12:05.790  MyWebViewClient          V   url (passed): https://smittenkitchen.com/ < view.getUrl(): https://smittenkitchen.com/ (called from: MyWebViewClient.onPageCommitVisible)
11:12:08.097                           D   url: https://smittenkitchen.com/, view: https://smittenkitchen.com/ (called from: MyWebViewClient.onPageFinished)
11:12:23.824                           D   url: https://smittenkitchen.com/?s=carrot, view: https://smittenkitchen.com/?s=carrot (called from: MyWebViewClient.onPageStarted)
11:12:24.083  MyWebView                V   javascript:window.HTMLOUT.processHTML(document.getElementsByTagName('html')[0].innerHTML); (called from: MyWebView.loadUrl < MyWebViewClient.onPageCommitVisible)
11:12:24.085  MyWebViewClient          V   url (passed): https://smittenkitchen.com/?s=carrot < view.getUrl(): https://smittenkitchen.com/?s=carrot (called from: MyWebViewClient.onPageCommitVisible)
11:12:25.176                           E   net::ERR_CONNECTION_REFUSED(-6) on request: https://ssc.33across.com/api/v1/hb?guid=cYCh20L9Or64olaKj0P0Le, https://smittenkitchen.com/?s=carrot (called from: MyWebViewClient.onReceivedError)
11:12:26.583                           D   url: https://smittenkitchen.com/?s=carrot, view: https://smittenkitchen.com/?s=carrot (called from: MyWebViewClient.onPageFinished)

Any idea what I could be missing in my implementation so that my WebView-based browser displays overlays like Chrome does?