Unable to save Markdown files after editing in Document Viewer Show more lines

[hongan1998611]

Bug

After editing a Markdown (.md) file in Document Viewer, the file cannot be saved.

When I try to close the file, VS Code asks whether I want to save the changes. Selecting Save does not work, and the file remains open with the same save prompt.

Steps to reproduce

1. Open a .md file with Document Viewer.
2. Edit the content.
3. Press Ctrl + S.
4. Try to close the file.
5. Select Save when prompted.

Actual result

The file is not saved and cannot be closed normally because the save prompt keeps appearing.

Expected result

The changes should be saved, and the file should close normally.