Hey @zhaoxi2000, thanks for following up, and sorry this is still happening on 3.22.7.
This is the same issue from your earlier thread: when chat is shown as tabs, the Preview / Markdown toggle can act on whichever tab has focus. If your cursor is still in the chat input when you click Preview, the chat tab gets swapped out and the chat panel closes. It’s still being tracked, and I’ve added your new report to it.
Until it’s fixed, either of these avoids it:
Click once inside the markdown file itself, then click Preview.
Or turn off chat tabs: Cursor Settings > General > “Open Chat as Editor Tabs”. With chat as a regular side panel, Preview no longer affects it.
If the chat does close, your conversation isn’t deleted. You can reopen it from the chat history.