Docs navigation menu not displaying on some pages.

[yassineS]

Description

The side menu for docs pages is not displaying consistently across pages. This is similar to #560.

Steps To Reproduce

1. Created docs pages, called "Wiki" in my case.

❯ tree content/
[ 192]  content/
├── [ 719]  _index.md
├── [  96]  about
│   └── [4.7K]  _index.md
├── [  96]  blog
│   └── [  31]  _index.md
└── [ 288]  wiki
    ├── [ 620]  _index.md
    ├── [ 256]  cv
    │   ├── [ 104]  _index.md
    │   ├── [2.6K]  experience.md
    │   ├── [ 550]  other.md
    │   ├── [ 192]  outreach
    │   │   ├── [1.5K]  _index.md
    │   │   ├── [ 676]  conferences.md
    │   │   ├── [ 471]  media.md
    │   │   └── [ 320]  public.md
    │   ├── [2.3K]  software.md
    └── └── [2.6K]  teaching.md

Expected Behavior Seeing this navigation menu in all pages:

Actual Behavior

The menu completely disappears in subpages. The new "sections" with content in _index.md file, but pages with any other name name.md lose the menu.

Environment

• Hugo Version: v0.146.3+extended+withdeploy darwin/arm64 BuildDate=2025-04-12T17:21:50Z VendorInfo=brew
• Browser/OS: MacOS
• Theme Version: v0.9.7