GH3 Problem with costant preview and ASSIST MF button

[stefanocps]

I have this problem. Seems like in manual when pressing/releasing Assist MF button,  the costant preview go wrong, or off i would say.In fact after that change in live view gets very small even if i rotate all the way the 2 setting aperure and shutter speed. And when i shut the pics come out with big difference form live view. Just like if  Costant preview goes off and in manual mode the button to set Constant Preview on/off don't work!So for now what i can do is switch off the camera, and when it goes on it works correctly again, Until when i press ASSIST MF. Now, i pleasntly ask to GH3 owner, if they have the same? Is it a bug? My camera has problem?Is there any setting to change this?

Thanks