Steps to reproduce

1. Create a page template.
2. Add two variables, one of type "Multi-line Text" and the other "List".
3. Add three different options to the List variable A, B, and C.
4. Create a page from that template.
5. Add several lines of text in the Multi-line Text box, and choose B or C in the List box, click Next.

Results

The text in the Multi-line Text box has totally disappeared and only the first option in the List variable shows, regardless of which was actually chosen.