RouterLink working exactly and only once

I have an application with a Menu on the left with two RouterLinks (say LinkA and LinkB) which navigate to the corresponding view.
But I have the following issue: Say I click on LinkA. This works, I get routed to ViewA. Then I click LinkB. This works as well. If I then click on LinkA again, I get routed to my root view! Same thing happens when clicking LinkB. I then stay on the root view and cannot navigate anywhere using RouterLink.
I can still navigate via the browser URL or a button that calls ui.navigate().
The thing I don’t understand is I’m using RouterLink the same way as in the docs and the same way our other Vaadin applications do. It works everywhere else, just not here.
Has anyone ever come across this?