If I close the "Discussion info" panel on the right while I'm partway through writing in a V5 discussion thread, will my content be lost?

It might. When you click "Close (X)" at the top right of the panel and the message "Unsaved changes will be lost" appears, choosing [Discard changes] abandons the content that hasn't been saved. 1. If you still want to keep your content, don't close the panel yet, and don't click [Discard changes] when the message appears. 2. If you want to check the content before sending, you can first click "Preview" on the right side of the input toolbar. 3. Once you are sure you don't want these changes, click "Close (X)" at the top right of the panel and choose [Discard changes] when the message appears. Note: This discussion currently has no sent attachments, so the "Attachments in this discussion" section does not appear in the "Discussion info" panel. This is normal.