Changing a constraint setting on a physics asset while PIE doesn't automatically update the skeletal mesh actor in the level that is using it.
If the user changes a setting that does cause a phys asset refresh, then the constraint settings will be updated.
RESULT
Actor in the level is not updated.
WORKAROUND
Change a setting on a body, which causes the physics asset to refresh.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-49669 in the post.
| 1 | 
| Component | UE - Simulation - Physics | 
|---|---|
| Affects Versions | 4.18 | 
| Target Fix | 4.19 | 
| Created | Sep 13, 2017 | 
|---|---|
| Resolved | Nov 20, 2017 | 
| Updated | Apr 27, 2018 |