My NavigationSplitView is very simple. The DetailView contains Table populated with data. SideBar populated with items that act as a filter for Table content. If I'm on the SideBar and hit Command-A, I never want to select everything in the sidebar. I always want to select all the content for a detail view. This is how Finder works.
I tried to set
List(...) {
...
}
.focusable(false)
When I launch the application, Command-A works exactly as I would like. But when I select another "filter" in sidebar with the mouse, the List becomes focusable.