No scrollbar in Debug build

[jkornelsen]

Steps to reproduce:

1. Open project 4b. Soriali Toolbox grammar
2. Drag bottom of Texts.txt window up above last line.

This should cause the scrollbar to appear but doesn't.

Similarly, moving the cursor down with arrow keys should scroll the view but doesn't. The only way to view offscreen content is by expanding the window.

When building as Release, this issue does not occur — scrollbar appears and arrow key navigation correctly adjusts the view.