bug(mat-form-field : outline) mat-label breaks when within a router-outlet

[Ploppy3]

Bug, feature request, or proposal:

mat-label breaks when within a router-outlet

What is the expected behavior?

What is the current behavior?

What are the steps to reproduce?

https://stackblitz.com/edit/angular-5yktv7?file=src%2Fapp%2Fhome.component.html

Which versions of Angular, Material, OS, TypeScript, browsers are affected?

Angular 6.1.0
Material 6.4.2
Chrome 68

[angular-automatic-lock-bot]

This issue has been automatically locked due to inactivity.
Please file a new issue if you are encountering a similar or related problem.

Read more about our automatic conversation locking policy.

_{This action has been performed automatically by a bot.}