Thank you, using flowchart instead of graph does the trick.
According to the Mermaid docs
a<--->b
should draw arrows on both sides. This does not work for me.
Could you add a keyboard shortcut or menu entry to quickly insert a frontmatter section template ?
The template could be in a file so it is editable. Copy / paste for every new file is not very comfortable.
Thanx for the good work.