This is something that we just fixed and will come out with 4.15.
For 4.14, if you take a look at MovieScene3DTransformTrackInstance.cpp, you’ll need to change:
SceneComponent->SetRelativeLocationAndRotation(Translation, Rotation);
To:
// If this is a simulating component, teleport since sequencer takes over.
// Teleport will not have no velocity, but it's computed below by sequencer so that it will be correct for physics.
AActor* Actor = SceneComponent.GetOwner();
USceneComponent* RootComponent = Actor ? Actor->GetRootComponent() : nullptr;
bool bIsSimulatingPhysics = RootComponent ? RootComponent->IsSimulatingPhysics() : false;
SceneComponent.SetRelativeLocationAndRotation(Translation, Rotation, false, nullptr, bIsSimulatingPhysics ? ETeleportType::TeleportPhysics : ETeleportType::None);