Frontmatter messes up the cursor logic

### Constly version

4.7

### Operating system

macOS (Apple Silicon)

### What happened

If you open a file with the content I've pasted below and then use the arrow keys to navigate the cursor around, you'll see the problem. 

### Steps to reproduce

```markdown
---
id: hero
anchor: ""
layout: stacked
slot: home
---

# heading

paragraph

**bold** text
```

### Anything else

_No response_