Docusaurus v2 - Docs link in Nav Dropdown without versioning

I'm creating a Docusaurus v2 project that will host documentation for a number of tools. They're all related, so it makes sense for them to be hosted in one place - but they're distinct enough that the docs for each should be separate.

As there are potentially a lot of these tools, I wanted to put the nav links in a dropdown, rather than having them fill up the entire width of the header. I'm trying the following:

themeConfig: {
  navbar: {
    ...
    items: [
      {
        to: '/about',
        position: 'left',
        label: 'About',
      },
      {
        position: 'left',
        label: 'Tools',
        items: [
          {
            type: 'doc',
            docId: 'intro',
            label: 'Tool 1',
            docsPluginId: 'tool1',
          },
          {
            type: 'doc',
            docId: 'intro',
            label: 'Tool 2',
            docsPluginId: 'tool2',
          },
          ...
        ]
      },
      ...
    ],
  },
}

This partly works, in that a drop down menu appears with the correct labels (Tool 1 and Tool 2) - but the links aren't clickable and aren't highlighted if the active page is one of the documentation tools.

Is this a bug, or am I doing something wrong?