Reproduction steps:
1. Open attached project
2. Open scene "Scene"
3. Notice in the scene view the smaller text is displayed
4. Play scene "Scene"
5. In game view the smaller text won't be displayed

NOTES:
Not all text disappears.

The smaller text disappears in scene view when you zoom in (watch "ZoomingIn.gif").

When canvas reference resolution x variable is below or equal 1150 the smaller text isn't displayed, but when it's above 1150 smaller text is displayed (watch "ChangingReferenceResolution.gif").

Resizing the unity windows also makes the smaller text to appear (watch "ResizingUnityWindow.gif").