Reproduction steps:
1. Create a new project
2. Create UI Document (Create > UI Toolkit > UI Document)
3. Double-click on UI Document to open UI Builder
4. Drag Help Box Element to Hierarchy
5. Select Help Box Element and enter long text in the Text field
6. Observe Help Box in the Viewport

Actual result: Help Box bounds extend vertically, but the additional space remains empty and the text does not fill the area
Expected result: Help Box bounds don’t extend vertically or text wraps and fills the extended vertical space

Reproducible with: 6000.5.0a1
Couldn’t reproduce with: 2022.3.68f1, 6000.0.62f1, 6000.2.12f1, 6000.3.0b10, 6000.4.0a5 (No Help Box Element)

Reproduced on: Ubuntu 24.04, macOS Sequoia 15.4 (M4)

Note: Issue is not reproducible with other elements