Lights and shadows flickering extremely

Hey folks,

I´ve always experienced some flickering of light in my scene but today the problem got extraordinary visible. I´ve recorded the problem and my Quality-settings. As the video shows, it only occurs if shadow-casting is enabled. Furthermore it seem to decrease noticeably if I change the shadow resolution to "low resolution".

-using deferred lighting

-There is no baked or realtime GI or baked lightmaps

-changing the pixel count doesn´t work

-deactivating all shadow-casting lights in the scene doesn´t work

-occlusion culling data is cleared

You can see all settings in the video :) https://www.youtube.com/watch?v=DTkpC1rl8Uw&feature=youtu.be

Thanks in advance!