Markdown preview stops updating with unsaved content if dragged out to a new Window (and back again)

[DanTup]

Not sure if this is expected or not - dragging a markdown preview out to its own window causes unsaved content to vanish and it stops updating.

Even dragging it back into the main window does not restore that behaviour. You need to close and re-open it.

markdown.mp4

If this is expected, are the restrictions on multi-window interaction like this documented anywhere?