Markdown: empty checkmark causes error on plain/rich edit modes

This issue respects the following points:

• I have read the FAQ
• I have searched for existing issues
• The issue affects the Notes Android app, neither the Notes server app nor the Nextcloud Android app.

Describe the bug

1. Create a new note
2. Make sure to be in rich editing mode (my note started out in rich editing)
3. Add a checkmark list with the following content:

• abc
• def

4. Now switch to "Plain edit mode"
5. back to "Rich edit mode".

The app claims the document has changed on the server versus the local version, showing the content side by side. When carefully inspecting the differences, the app renders a checkbox whereas the server version renders as a bullet followed by litteral content "[ ]".

Expected behavior

The server and app agree on the content being a checkbox with without following content, as the content of the note did not change between the mode switches.

Notes Android version

4.3.1

Notes server version

4.12.1

Nextcloud Android version

3.32.1

Nextcloud version

30.0.12

Device

Motorola Moto g73 5g

Android Version

14

App Store

• Google Play Store
• F-Droid
• Huawei App Gallery

Stacktrace

No response

Reproduce the issue by creating the three-item checklist, switching from rich edit mode to plain edit mode and back, then compare the displayed local and server content. Trace the plain/rich mode conversion and checkbox handling for an empty item; done means an empty checkbox remains a checkbox and no server-conflict warning appears after switching modes.