Docker – jupyter notebook export omits markdown

Given a jupyter notebook (here Test_Export.ipynb) with the following content:

{
 "cells": [
  {
   "attachments": {},
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "This is markdown."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print('This is code.')"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3 (ipykernel)",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.11.4"
  },
  "orig_nbformat": 4
 },
 "nbformat": 4,
 "nbformat_minor": 2
}

I’d like to export the executed notebook without input code to asciidoc format. In order to do that, I use the offical docker image and execute:

docker run --rm -it --entrypoint /bin/bash -P -v ${PWD}:/home/jovyan/ jupyter/minimal-notebook:notebook-6.5.4 -c "jupyter nbconvert --execute --to asciidoc --no-input Test_Export.ipynb"

The result looks as follows:

----
This is code.
----

Somehow any markdown area is completely omitted which is the case for base-notebook image and minimal-notebook one. Using datascience-notebook image, the markdown sections are correctly exported to the asciidoc file.

Why is that?