App closes when calling async methods synchronously

          Hi, I made simple WPF example where we can reproduce the same exception and finally application closes.  

I think here is problem with binded async method and threading;
In my example I just call javascript method in DevTool console : window.chrome.webview.hostObjects.sync.customactions.GetString("aaa") that is binded to :

    [ClassInterface(ClassInterfaceType.AutoDual)]
[ComVisible(true)]
public class CustomActions
{
	public async Task<string> GetString(string str)
	{
		return await Task.Run(() => str);
	}
}

I used last nuget package version 1.0.1462.37. I can share this example.
If here is my configuration error please let me know how can properly bind and use asynchronouse method
regards :)

Originally posted by @53b4 in https://github.com/MicrosoftEdge/WebView2Feedback/issues/3062#issuecomment-1381484122

AB#43012834

Start with the WPF reproduction and the DevTools call to window.chrome.webview.hostObjects.sync.customactions.GetString("aaa"), then inspect the CustomActions.GetString async method shown in the issue. Compare synchronous host-object invocation with the asynchronous return value; done means the application no longer closes and the supported binding or usage is clear.