Reproduction steps:
1. Open the "New Unity Project.zip" project
2. Select "Plane" Game Object
3. In the Inspector "Cloth" component press "edit cloth constraints"
4. Select the right Scene view where the Cloth GO is viewed from above
5. Notice that the Constraint dots are visible
6. Select the left Scene view where the Cloth GO is viewed from below
7. Notice that the Constraint dots are not visible

Expected Result: Constraint dots are always visible
Actual Result: Constraint dots are not visible from all angles

Reproduced with: 2020.1.0a21, 2019.3.0f6, 2019.2.20f1, 2018.4.16f1, 2017.4.36f1