Screen space widget on mirrored display while using VR in 5.4

A couple of years ago I did a VR project for work that included a start up menu rendered on the mirrored window on the display when the HMD was in use. This had the purpose to let a person do some setup before starting the VR experience. It was important that it wasn’t done by the person wearing the HMD. I remembered it as quite easy, just do a normal Create Widget->Add to Viewport flow and it would render the UI on the mirrored window on the display and not the HMD. But now when I’m trying to do it it won’t work. I don’t get the different renders between the HMD and display. Have they changed something since 5.1 that affects this? Or do I forget/miss something?