How to reproduce:
1. Open "Basketball - Cloth Bug" Unity project
2. Enter Play Mode
3. Take the ball with E and throw it to the net with left mouse button
- Notice that the net acts normally
4. Exit play mode
5. Select "hoop+street01 -> "backboard" -> "net" in the hierarchy
6. In the inspector in cloth section select second "Edit cloth self or inter collision "
7. Check Manipulate backfaces and select all the dots on the net
8. Enter Play Mode and notice that the net is stiffed, the only one way to fix is to restart Unity

Expected result: Cloth self or inter collision should change with checkboxes
Actual result: Cloth always stay stiffed and the only one way to fix is to restart Unity

Reproducible with: 2018.2.0a9, 2018.1.0f1, 2017.4.1f1, 2017.3.2f1,

Note:
Cannot check on 2017.2 and earlier versions because it has no "Edit cloth self or inter collision "
User's video how to reproduce this issue:
https://www.youtube.com/watch?v=4W6DrvlPYM8&t=8s