qtFred Bug: Briefing Last Stage Issue

<img width="720" height="137" alt="Image" src="https://github.com/user-attachments/assets/201c45db-e7c4-4f59-a968-6fbfddc5b6f1" />

This may or may not be fixed in the newer version of the briefing editor.  I have not yet reproduced, as I'm just trying to record issues before they get buried. 