Rich MarkDown content in Jupyter notebooks not rendered

Summary

Rich MarkDown content in Jupyter notebooks is not rendered correctly. Equations and attached inline images are for example not shown.

I was under the impression with #18258 (closed) closed and released in 13.8 notebooks should be rendered correctly.

Steps to reproduce

Add the notebook https://gitlab.com/teake/jupyter-notebook-test/-/blob/master/test_notebook.ipynb to a project, and view as "Display notebook".

Or add an inline MarkDown image to a notebook (by dragging it onto a MarkDown cell), save it, and upload it to a project.

Example Project

https://gitlab.com/teake/jupyter-notebook-test/

What is the current bug behavior?

Looks like this:

What is the expected correct behavior?

Should look like this:

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com.