A long time ago I had to choose between two video cameras (camcorder), JVC EVERIO GZ-GX1 or PANASONIC HC-V720 ~ And the winner was JVC!
Panasonic intentionally disables HDMI output when using WiFi remote control. Why ?
Perhaps to force you to buy another camera that offers this feature. Even the cheapest competitive JVC camcorder offers HDMI + WiFi without any problem.
My personal NOTE: Panasonic = Overpirced and “Evil” … Absolute waste of money !!!