On Darkroom, go to the event that you're on,
Output Settings and select Camera,
make sure to have the YUY to MJPG.
That should fix the issue of a laggy LiveView

Change camera resolution to 1080p

 

If you want to change the camera settings, you can select the "CAMERA PROPERTIES" BUTTON from there
You can change Saturation, Contrast, Brightness, Focus, ETC

CAMERA PROPERTIES

 

 

 

 

If you think you messed up the camera settings to no return remember you can always set it back to default

settings by clicking the "Default" button.