With any Micro single/SLR camera, only one of the HDMI video outputs and the camera's screen display can be enabled when you are recording 4K video because of the limitation of the camera itself. So you can try to set the shooting format to 1080. Photography cameras do not have this limitation.

If you want to use a Micro single/SLR camera to record 4K video and monitor the shooting simultaneously, you can connect Camera->ATOMOS Recorder->Transmitter