I recently bought the Metz Mecablitz 58 AF-2 for use in the wireless mode with a Lumix GX-7. The Slave Mode works flawlessly. It's a great flash and easy to use...except for the Servo mode. I'm not sure what I'm doing wrong, but it seems that sometimes I can get it to work, but most of the time it doesn't sync using the GX7 pop-up flash. Is there some trick that is not explained in the manual for using the Servo mode with a Panasonic pop-up flash?