[TOC] includes headings inside list items (e.g. `- ### Case1`) in the table of contents

[tsungjung411]

Is this a hackmd.io issue?

• Yes, the bug happens on https://hackmd.io
• No. If it's a self-hosted CodiMD instance, please fire up the issue in the repo of CodiMD: https://github.com/hackmdio/codimd

Read our Official tutorial

It's on https://hackmd.io/c/tutorials/

or Chinese version: https://hackmd.io/c/tutorials-tw/

What's the problem

Current behaviour

When using [TOC], headings written inside list items are also included in the table of contents.

Reproducible content:

[TOC]

### Section
- ### Case1
- ### Case2
- ### Case3

Actual rendered TOC result:

- Section
- Case1
- Case2
- Case3

Provide steps to reproduce:

1. Go to https://hackmd.io

2. Create a new note

3. Paste the content below:

   [TOC]
   
   ### Section
   - ### Case1
   - ### Case2
   - ### Case3

4. Switch to preview / rendered view

5. Observe that Case1, Case2, and Case3 are also included in TOC

Here is an example: https://hackmd.io/mhkr3m9WR4Kse_ePoV_c6w
(This never happened before.)

Expected behaviour

I would expect only the main section heading to appear in the table of contents:

- Section

Headings inside list items such as - ### Case1 should ideally not be included in TOC, or this behavior should be clearly documented if it is intended.

Environment

I use HackMD on:

Desktop

• OS: Windows / Ubuntu 24.04 / Android 14
• Browser: Chrome 147.0.7727.56 , FireFox 143.0（64 位元）

Mobile

• Device: Xiaomi Pro 13
• OS: Android 14
• Browser: Chrome 146.0.7880.177

Additional context

This may be intended Markdown parsing behavior, but from a TOC usability perspective it is surprising and can pollute the generated table of contents.
If this is expected behavior, documentation clarification would be helpful.