Turns out I had to include the path to the navigator as well in the path.

Updated config to:

const config = {
  screens: { // Root navigator: Menu Nav
    StackNav: {
      screens: {
        TabsNav: {
          path: '/places',
          screens: {
            Screen1: `/summary`,
            Screen2: '/stats',
          },
        },
        Screen3: '/account'
      }
    },
    Screen4: '/chat'
  }
}

...and updated the linkTo from /stats to /places/stats.

Snack: https://snack.expo.dev/@acrabb713/143a82