ChromiumWebBrowser - how to set height to HTML doc height - html

Question

I have a chromiumWebBrowser hosted in my application.
user can navigate between html pages (with binging to address).
I need xaml scroller (not css), so I have a scrollViewer and inside the Chromium browser.
Every time the Address changes, chromium height needs to be full html doc height, to get the scrolling right.
I have tried setting it similar to answer in this Q:
cefSharp ChromiumWebBrowser size to page content
which works well first time, but when navigating, it only grows - if first page is 600, and next is 200 - it returns 600 second time too.
XAML:
<ScrollViewer x:Name="scroller" >
<wpf:ChromiumWebBrowser x:Name="chrome"
Address="{Binding CurrentUrl}" />
</ScrollViewer>
C#:
chrome.LoadingStateChanged += async (s, e) =>
{
if (!e.IsLoading) // browser.CanExecuteJavascriptInMainFrame == TRUE !
{
JavascriptResponse response =
await chrome.EvaluateScriptAsync(
// GET HEIGHT OF CONTENT
$"(function() " +
"{ var _docHeight = " +
" document.documentElement.scrollHeight; " +
" " +
" return _docHeight; " +
"} " +
")();");
int docHeight = (int)response.Result;
chrome.Dispatcher.Invoke(() => { chrome.Height = docHeight; });
}
};