Why does page not update after refresh when .cshtml changes

After Asp.net Core 3.0, Runtime compilation is enabled using the Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation package.
To enable runtime compilation, apps must:

Install the Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation NuGet package.

Update the project’s Startup.ConfigureServices method to include a call to AddRazorRuntimeCompilation:

services
    .AddControllersWithViews()
    .AddRazorRuntimeCompilation();

or

services.AddMvc().AddRazorRuntimeCompilation();