Difficulties with custom 404 page

Questions
1

I am use Umbraco v13.3.0 and uSkinned v6. I am trying to send 404 errors to a custom page I have created. I have added the Error404Collection property to the appsettings.json file, but it doesn’t seem to do anything. I have tried with ContentXPath, ContentId, and ContentKey.

I have a custom middleware class for catching and logging errors in custom code. I found I was able to redirect to my custom 404 page by doing something like this, but I don’t really like relying on JavaScript for this.

Note: context.Response.Redirect was also not working in the below class as I expected.

public async Task InvokeAsync(HttpContext context){
		try
		{
            await _next(context);

            if(context.Response.StatusCode == (int)HttpStatusCode.NotFound)
            {
                string redirecTo = "/my404";
                _logger.LogError("trying to redirect (404) from " + context.Request.Path);

                //context.Response.Redirect(redirecTo);

                await context.Response.WriteAsync($"<script>window.location='{redirecTo}';</script>");
            }
        }
        catch (Exception ex)
	{
          //log errors here
        }
}

I feel like I am missing something. Does anyone have any suggestions on what I can try next?

This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/114045-difficulties-with-custom-404-page