Level 2 headers not always expanded below "On this page"

🔍 Before submitting the issue

[X] I have searched among the existing issues
[X] I am using a Python virtual environment

🐞 Description of the bug

I have a RST page with two levels of headers:

Title1
  Subtitle 11
  Subtitle 12
  Subtitle 13
Title 2
  Subtitle 21
  Subtitle 22
  Subtitle 23
Title 3
  Subtitle 31
  Subtitle 32
  Subtitle 33
Title 4
  Subtitle 41
  Subtitle 42
  Subtitle 43

open the the HTML page

resize the browser window height to display

Title1
 Subtitle 11
 Subtitle 12
 Subtitle 13
Title 2
 Subtitle 21
 Subtitle 22
 Subtitle 23
Title 3
 Subtitle 31

On the HTML page:

in "On this page", click on "Title 4" => "Title 3" is selected and expanded whereas I would expect "Title 4" to be selected and expanded
in "On this page", click on "Title 2" => "Title 1" is selected and expanded whereas I would expect "Title 2" to be selected and expanded

ansys-theme-bug-onthispage.zip

📝 Steps to reproduce

python -m venv .venv
.venv\Scripts\Activate.ps1
python -m pip install sphinx ansys-sphinx-theme
sphinx-build -M html . _build

Then open _build/html/page1.html (tested with Edge 117.0.2045.60 on Windows 11)

💻 Which operating system are you using?

Windows

📀 Which ANSYS version are you using?

ansys-sphinx-theme 0.12.3

🐍 Which Python version are you using?

3.9

📦 Installed packages

accessible-pygments==0.0.4
alabaster==0.7.13
ansys-sphinx-theme==0.12.3
Babel==2.13.0
beautifulsoup4==4.12.2
certifi==2023.7.22
charset-normalizer==3.3.0
colorama==0.4.6
docutils==0.20.1
idna==3.4
imagesize==1.4.1
importlib-metadata==6.8.0
Jinja2==3.1.2
MarkupSafe==2.1.3
packaging==23.2
pydata-sphinx-theme==0.14.1
Pygments==2.16.1
requests==2.31.0
snowballstemmer==2.2.0
soupsieve==2.5
Sphinx==7.2.6
sphinxcontrib-applehelp==1.0.7
sphinxcontrib-devhelp==1.0.5
sphinxcontrib-htmlhelp==2.0.4
sphinxcontrib-jsmath==1.0.1
sphinxcontrib-qthelp==1.0.6
sphinxcontrib-serializinghtml==1.1.9
typing_extensions==4.8.0
urllib3==2.0.7
zipp==3.17.0

ansys / ansys-sphinx-theme

Level 2 headers not always expanded below "On this page" #314