To reproduce:
1. Open the "SceneMenu" scene in the user-provided project
2. Enter the Play mode
3. In the Scene, note that MenuUI/Boxes/Thing/Stuff/Text is outside the viewport
4. Press the "Click me" button
5. In the Scene, note that MenuUI/Boxes/Thing/Stuff/Text is brought inside the viewport but its parent Stuff is still inactive
6. In the Game view, press the "Click me too" button

Desired outcome: The text is visible and is rendered in the current position of the "Text" Game Object.
Actual result: The text is not visible and is rendered in the old position of the "Text" Game Object.

Note: UI element gets rendered correctly after modifying the size of the Game view window.

Reproduced with 2017.1.0b9, 2017.1.0p5, 2017.3.0a1, 2017.3.0a2
Not reproduced with 5.5.1f1, 5.5.4p4, 5.6.0b3, 5.6.3p1, 2017.1.0a1, 2017.1.0b8, 2017.2.0b8, 2017.3.0a3, 2017.3.0a5
Regression introduced in 2017.1.0b9

Fixed in 2017.2.0b8