markdown not working on iPadOS

### Expected

after enabling markdown, inputting with md grammar, and exited editor, the md content should be displayed as formatted

### Observed

the content is still unformatted
### Reproduced

1. Go to iOS Simplenote
2. Write something in markdown, and enable markdown support, exit the editor then click open the note
3. the markdown content is not formatted

### Where did you see the bug

- System Make: Apple
- System Model: iPad (9th generation)
- OS: iPadOS
- OS version: 18.3.2
- Browser (if applicable):
- Browser version (if applicable):
- Simplenote app version: 4.55


The issue names no source files, tests, or entry points. First reproduce the report with Simplenote 4.55 on the listed iPadOS setup, checking the transition from editing to reopening a note; done means markdown content is displayed as formatted after leaving and reopening the editor.

Written by the indexing model from the issue text.