Nested <ion-router-outlet> is appending instead of replacing

For some reason I do not understand the content of every route the user navigates to gets appended to the nested ion-router-outlet, however, when I reload the page the component loaded is the one that matches the URL.

I have tabs working in my local with ion-router-outlet working as expected, however, I’m not able to figure out why in this other case isn’t working as expected. Any help?

a small sample project showing the behavior would be helpful