This simple demo app is part of an updated article on theCodeCampus blog. The article can be found here.
This example uses Angular 7 and Material 2.

Follow this link.

My guess is your using Angular in combination with Angular Material and you need a sticky footer, which is under given circumstances not well documented.
The footer supports a variable height.

The most important file is src/app/app.component.scss. There you can find the scss rules to support a sticky footer.

Clone this project and run ng serve for a dev server. Navigate to http://localhost:4200/.