„Smooth Cut“ transition with wired effects

Does anybody can tell me why „Smooth Cut“ leeds to short deformations of the edge regions and to a short dimming? > See the attached three pictures: (1) normal picture/frame, (2) the picture/frame right before the „Smooth Cut“ window, (3) in the middle of the „Smooth Cut“ window – exactly where the cut is .

I have used the „Smooth Cut“ tool many times in other videos/projects without getting this wired effect. So I tried to open an older project that contained „Smooth Cuts“ without deformations and dimming, than copied clips with wired „Smooth Cuts“ from the actual project in the older one. The deformations and dimming continued but only in the clips that I had copied.

So, I guess that – by mistake – I did so adjustments. And now I have no idea how to reverse it.

Does some of you?

Thanks, Martin