Refreshing an open Markdown file renders a blank document

[jmojiwat]

Steps to Reproduce

1. Open ReadMark and load any local .md file containing valid Markdown content.
2. Verify that the document renders correctly in the viewer.
3. Trigger a document refresh (via the refresh button / shortcut).
4. Observe the viewer pane.

Expected Behavior

ReadMark should reload and re-render the contents of the .md file from disk without clearing the view.

Environment

ReadMark 1.2.77 Windows 10 22H2 (OS Build 19045.6466)