Annoying bug that has appeared since upgrading our project from UE4.7 to UE4.8. I suspect it is linked to this bug (JIRA UE-15268).
Basically I have an actor (blueprint) with a physics-simulated static mesh as root component. When this is used via a ChildActorComponent spawn location and scale are not correct. It also only seems to happen when object is spawned dynamically (rather than simply dragged into scene).
A work around is to disable simulate physics and enable it after one frame.
Create actor with a static mesh as root component
Enable physics simulation on that mesh
Create another actor with a child actor component referencing first actor
Reposition child actor component (and scale if you want)
Spawn containing actor in level dynamically
Observe location is not correct
I have created a pair of assets that produce effect.
[Child actor: **]
[Containing actor: **]
They use only starter content assets so you should just be able to import them. You’ll need to spawn Repo_Container in level blueprint.
I was able to reproduce this issue. I’m not entirely sure it is related to JIRA that you listed above so I created JIRA UE-18762. Our developers will be investigating it further and we will post back here with additional info if needed.
An additional workaround besides one you mentioned above is to make root of first blueprint a SceneComponent instead of StaticMesh.