Manual testing - distancefieldtext text disappears/reappears with certain angles

In the manual test distancefieldtext, portions of the displayed text tends to disappear/reappear when located in various distances away from the camera.

Steps to reproduce:

1. Run the manual test.
2. Do not change the font, and do not left-click "Bold" or "Italic".
3. Notice that the outermost portion of the text become visible when it is as far away from the camera as the changing angle allows, and this portion of the text will disappear again when approaching the camera.
4. Repeatedly left-click the area in which the text is displayed until four rows of characters have been displayed. Notice that the disappearance/reappearance happens during the middle of the animation, when there seems to be no angle applied to the text.

Expected behavior:

Portions of the text should not disappear when the angle of the text is changing.

Observed behavior:

Portions of the text may disappear/reappears in certain angles. These portions and angles differ with varying fonts, and having "Bold" and "Italic" enabled.