Duplicated nav content when using text mode browsers

[lancea-tech]

• I confirm that this is an issue rather than a question.

Bug report

Duplicated nav content when accessing VuePress site via text mode browsers (like links or lynx).

Steps to reproduce

1. Access site with nav section using text mode browser (like links or lynx).

Site where problem was observed: https://lancea.pl/

themeConfig:

    themeConfig: {
        search: false,
        sidebar: false,
        logo: '/logo.svg',
        nav: [
            { text: 'Strona Główna', link: '/' },
            { text: 'Usługi', link: '/services/' },
            { text: 'O nas', link: '/about/' },
            { text: 'Kontakt', link: '/contact/' }
        ]
    },

What is expected?

Same content displayed in both graphics mode browsers like Chrome and text mode browsers like links or lynx.

What is actually happening?

Text mode browser displays nav content twice.

Chrome:

Links:

Other relevant information

• Output of npx vuepress info in my VuePress project:

Environment Info:

  System:
    OS: Windows 10 10.0.18363
    CPU: (12) x64 Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
  Binaries:
    Node: 12.16.1 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.0 - C:\Program Files (x86)\Yarn\bin\yarn.CMD
    npm: 6.14.2 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: 44.18362.449.0
  npmPackages:
    @vuepress/core: Not Found
    @vuepress/theme-default: Not Found
    vuepress: ^1.4.0 => 1.4.0
  npmGlobalPackages:
    vuepress: Not Found