Mermaid Graphs in Milestones

Since at least Gitlab v15.8.0 we have noticed that using mermaid graphs do not work in milestones. I am not sure if this did not work in the past though, i.e. if it does not work by design or if something is broken. As an example I tried using:

graph TD;
  A-->B;
  A-->C;
  B-->D;
  C-->D;

which does not render (in a milestone's description)