Reported in UDN: [Link Removed]
Reimporting a static mesh asset from an FBX file causes collision to disappear on spline meshes referencing the static mesh asset.
In investigating this so far, I noticed that USplineMeshComponent::RecreateCollision() gets called twice during the FBX reimport process. And later in FKAggregateGeom::GetAggGeom() and FKConvexElem::DrawElemWire() although the ConvexElem appears to have the correct values, the underlying PhysX collision structure has been reset to default values.
Steps to Reproduce:
The collision box disappears until you clear the static mesh property and reassign it.
The collision box is updated to represent the collision for the spline mesh based on the reimported static mesh.
There's no existing public thread on this issue, so head over to AnswerHub just mention UE-134572 in the post.