pawn camera control with child actor in VR

Hi,
I’ve hit a problem with my camera on my custom player pawn. I’ts a VR camera with “lock to HMD” enabled

I’m trying to use a child actor component with its own spring arm/camera in it, instead of directly having the spring arm/camera on the pawn itself as components.

when i press play, the camera always just sits at the 0 0 0 position of the pawn, like it is completely ignoring the spring arm length. The HMD rotation and positional tracking still work.

If however I just add a spring arm/camera as normal components with the same settings as those in the child actor, things work just fine.

Any idea why the spring arm length is not having an effect?