HDMI via BlackMagic Decklink Mini 4k

Playing around trying to get my Sony alpha into Unreal via the HDMI on a BM decklink mini 4k. Using the standard VirtualProduction template and LiveComp map in UE4.24.3. I have a BM Media Source available to select in the Media Profile but no success getting any footage in, MediaPlate is just white. The card is definitely capturing fine, I can see the video in OBS. Any thoughts on this? I have seen a few people post they have got HDMI running in here with the same card. Thanks for the advice.