When using non Panasonic lenses sometimes the extended focus works by either pushing in the shutter/aperture wheel or pressing the touch screen, and then without changing settings, and for no apparent reason, the extended focus will just stop working. Pressing the screen or wheel won't work. Shutting down and restarting the camera doesn't get it working. I'm trying to use the feature with some fast lenses where focus is critical, so any help would be appreciated.