Displaying an IPython Markdown widget with a custom div inside it does not work in voila

[dou-du]

Hi,

We are working on a Jupyter extension to reprint the code easily. Basically, we need
put a custom <div> generated by the Markdown. (as shown below for the second
display).

However, the voila is not working for our second display. The results are shown in figure
below:

Is there a way to solve this problem ? Thanks a lot for helping.

[giovannipizzi]

Indeed, it would be great to have a pointer of what could be the problem - we would be happy to contribute with a PR if some developer could point us to the point in the code where we should look into.
As a reference, the full widget is reprint-magic - the example above by @dou-du is the minimal example to illustrate the issue we are facing. Thanks!