Can't make highlighting work for Mermaid diagrams

[MurzNN]

I create a Quarto document exactly like in the documentation:

---
title: "Mermaid highlighting"
format: html
filters:
  - quarto
  - line-highlight
---
```{mermaid}
%%| echo: true
%%| ht-pattern: "%%<<"
flowchart LR
  A[Hard edge] --> B(Round edge)
  B --> C{Decision}
  C --> D[Result one] %%<<
  C --> E[Result two]
```

But it produces an error:

Syntax error in text
mermaid version 11.12.0

here is a screenshot:

How to fix this issue?