Light and shadow and a bruise

I bought the LX7 as a supplement to my DSLRs. The decisive factors were good experiences with a TZ7 and high luminous intensity. The first photos were also very promising, in daylight and sun behind the picture quality was quite comparable with a Nikon D90 (not affiliated with a D7100). Of course, only at full size. A difference in quality is visible but once you get magnified. Thus, I also counted.
Not expected I have a disastrous image quality with lateral light from the front and backlit subjects.
It caused stains (no Lens Flaire) in the image that are not acceptable. Especially in the middle of creating one large bruise, like a fog. Whether it is an objective problem or a sensor problem I can not sagen.In various forums I have, unfortunately too late, read about it and also tried all the help tips. These alleviate the problem, but to eliminate it is not 100%.
I bought the device at your local supplier (even cheaper than Amazon) but I have six weeks no chance of return.
But there is also a little positive to report. When shooting at night (freehand), the LX7 proposes well thanks to the high light intensity. And the videos are watchable.
Conclusion: if you carefully photographed, so watch out exactly where the light comes in and changes the image section accordingly until there is no fog, you can live with it. If in some lighting conditions (backlit) with the display but difficult. From the originally planned purchase of the electronic viewfinder, I have refrained my experience with the camera.
Manual giving only on CD.
It would interest me whether the identical Leica D-Lux also has this problem.
I'll bring the camera to Panasonic Service in a new year.