How to render pd.DataFrame table in pdf with nbconvert+pandoc

I am generating a pdf from a set of Jupyter notebooks. What I do is to (for each ipynb)

$ jupyter-nbconvert --to markdown Untitled1.ipynb

and them merge them with

$ pandoc Untitled1.md [Untitled2.md ...] -f gfm --pdf-engine=pdflatex -o all_notebooks.pdf

(I am mostly following the example here). One thing I noticed is that the pandas DataFrames such as

import pandas as pd
df = pd.DataFrame({'a':[1,2,3]})
df.head()

are rendered in the pdf as

rather than

Any idea how to fix this issue, please? I am using $ jupyter-nbconvert --version 5.6.1 and $ pandoc --version 2.9.2.1. In the md file the table turns into the html block below. I suspect pandoc does not interpret it correctly. I tried the from-markdown-strict option suggested here, without any luck.

Thank you!

<div>
<style scoped>
    .dataframe tbody tr th:only-of-type {
        vertical-align: middle;
    }

    .dataframe tbody tr th {
        vertical-align: top;
    }

    .dataframe thead th {
        text-align: right;
    }
</style>
<table border="1" class="dataframe">
  <thead>
    <tr style="text-align: right;">
      <th></th>
      <th>a</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <th>0</th>
      <td>1</td>
    </tr>
    <tr>
      <th>1</th>
      <td>2</td>
    </tr>
    <tr>
      <th>2</th>
      <td>3</td>
    </tr>
  </tbody>
</table>
</div>

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