Just received my GX7, but the camera does not trigger either of my 2 600R flashes. The camera seems to "recognize" the flash when mounted in the hotshoe (i.e. flash icon appears on the screen". I mimic the settings from MY GH3 to the GX7....auto-TTL settings. On my GH3 the flash fires; on the GX7 the flash does not fire. Is there a "secret" setting somewhere for the GX7, or do I have a defective unit?