Problem with VR plugins in packaged project

When I package a project with the VR plugins enabled it doesn’t run at full screen - it sticks to a borderless 1080 window. If I disable the VR plugins I get the following error:

Error: CDO Constructor (OculusMR_CastingCameraActor): Failed to find /OculusVR/OculusMR_RenderTarget

Any ideas what this might be? Google doesn’t bring up much.

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