To reproduce:
1. Open attached Unity project "Header.zip"
2. Open "gg" scene
3. Click on Main Camera and observe the "HeaderTest" script component

Expected result: There should be two headers in the script component - "Attributes" and "Unity Setup Fields"
Actual result: Only "Attributes" header is visible, because it is followed by a public variable (Open up the "HeaderTest" script to observe)

Note: in the "HeaderTest" script, under the "Unity Setup Fields" header, change the private string enemyTag to public, save and check the script component again. "Unity Setup Fields" header will be visible now.

Reproduced on: 5.5.4p2, 5.6.2p3, 2017.1.0f3, 2017.2.0b3