AspNet-Core2-Page-Route-Problem

Problem: adding the following;

@page "{id?}"

to the top of a page causes it to pick up the route of other pages.

Produce:

1. Out-of-the-box asp.net core2.1 WebApplication
2. Add the following to contacts.cshtml and about.cshtml

@page "{id?}"

3. Route to;

https://localhost:44306/About/hello

4. Now click on "Contacts" in the NavBar.

You will be routed to

https://localhost:44306/Contact/hello

HWhattt?

I have tried replacing;

  app.UseMve();

with

 app.UseMvcWithDefaultRoute();

Still the same problem.