Is there any possibility to have custom "notfound.cshtml" per default? Can not do anything to have my own "notfound.cshtml" static. I know there is the way over umbraco to create custom DocType notfound inside CMS and define it as 404er.

It does not matter what I do, on 404 always comes result from umbraco/UmbracoWebsite/NotFound.cshtml file

This is my Pipe:

if (!context.HostingEnvironment.IsEnvironment("Production"))
{
    app.UseDeveloperExceptionPage();
}
else
{
    app.UseExceptionHandler("/Error/500");
        //Issue https://github.com/umbraco/Umbraco-CMS/issues/11851
        //app.UseStatusCodePagesWithReExecute("/Error/{0}");
}

app.UseHttpsRedirection();

app.UseUmbraco()
   .WithMiddleware(u => {
    u.UseBackOffice();
        u.UseWebsite();
   })
   .WithEndpoints(u => {
    u.UseInstallerEndpoints();
        u.UseBackOfficeEndpoints();
        u.UseWebsiteEndpoints();
   });

app.UseStaticFiles(new StaticFileOptions() ...
app.UseSpa(spa => ...

Does anyone knows why this does not works or what am I doing here wrong?