All Micro single/SLR camera, only one of HDMI video output and 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 as 1080.
But Photography/Video camera does not have this limitation, it supports HDMI video output and the camera’s screen display simultaneously.
If you insist to use Micro single/SLR camera recording 4k video and monitoring the shooting simultaneously, please connect Camera->ATOMOS Recorder->Transmitter.