I have Nikon D3300. Its sync speed should be 1/200, but when I shoot with strobes, I have a black bar at the bottom of any image. When I change the shutter to 1/160, the black bar is gone. Where could be the problem? I use GODOX SK 400II strobes with Godox XT-16 transmitter. I didnt noticed this problem when I used speedlites. I also noticed slight motion blur on some portraits when shooting with the strobes. Even at 1/160 with 50mm lens. I didnt noticed any motion blur on similar photos when I used speedlites before I bought strobes and I didnt noticed anything like this when I shoot events without any flash/strobe. Any ideas where could be the problem?