absLangURL and relLangURL do not generate the correct link

config.yaml

baseURL: https://example.com/myblog/
languageCode: en-us
defaultContentLanguage: en-us

menu:
  main:
    - name: Home
      weight: 10
      identifier: home
      url: /
    - name: Archives
      weight: 40
      identifier: archives
      url: /archives/

languages:
  zh-cn:
    contentDir: content/zh-hans
    title: 我的博客
    languageName: 中文
  en-us:
    contentDir: content/en-us
    title: My Blog
    languageName: English

baseof.html

{{ range .Site.Menus.main -}}
    {{- $url := .URL | relLangURL -}}
    {{- $url -}}
{{- end }}

Output

localhost:1313/myblog/

/myblog/myblog/
/myblog/myblog/archives/

localhost:1313/myblog/zh-cn/

/myblog/zh-cn/myblog/
/myblog/zh-cn/myblog/archives/

Expected

localhost:1313/myblog/

/myblog/
/myblog/archives/

localhost:1313/myblog/zh-cn/

/myblog/zh-cn/
/myblog/zh-cn/archives/