Visual Studio 2017 does not offer quick action

Question

I created a new ASP.NET Core project in my new VS2017 installation:

I open Startup.cs, create a ctor method and write inside it:

var configurationBuilder = new ConfigurationBuilder() 

I don’t even end the line with a semicolon, and a yellow light appears on the left, it VS offers me a quick action to add

 using Microsoft.Extensions.Configuration 

This is what I consider the usual behavior of VS.

However, just a few lines down when I try to use AddMvc () in the ConfigureServices () method, there are no light bulbs, no quick action is suggested. Therefore, when I type the following:

 services.AddMvc(); 

I got stuck with an error until I manually open the Nuget package manager and explicitly add Microsoft.AspNetCore.Mvc

I had no such problems in VS2015 because I was always offered a yellow light, after which I pressed CTRL +. and then Enter to load the correct files.

Here's what my respective VS17 options look like:

USE OF DIRECTIVES

GENERAL INFORMATION

PACKING SOURCES

Does anyone else have the same problem? I installed VS17 on my computer for friends (she kindly allowed me), and still there. There is no light bulb to automatically prompt me to download Nuget.