To reproduce:
1) Create new project
2) Add a cube to a scene
3) Enable edit mode on box collider of cube to see the pivots

Notice it works as Expected

4) Disable edit mode to hide the pivots
5) Create another inspector tab (for better clarity, separate those tabs so that you would see both at once)
6) Enable edit mode using the newly created inspector tab

Actual: Pivots don't appear

Reproduced in 2017.1.0f3, 2017.4.0f1, 2018.2.0a8