Opencv Videocapture not accept set properties


I try to make some imageprocessing on a usb camera video stream. I started with a python script which was handy beacaue it read the frame into a np array with my capture prop settings. But when i switched to c++ i noticed a different behavior. It looks like the videocapture not accept any of the prop flags i set. Can someone explain this phenomena to me? I working on windows currently, with DSHOW backend, other backends not worked with the c++ code.