I see into the work of YOLO in pytorch . Then I run detection with  yolov3.cfg  ,  yolov3.weights  and coco.names (80 class list) all working good at video and images, and accuracy too fine. But if I change  cfg  to   yolo3_openimages.cfg 2weights to  yolov3-openimages.weights  and openimages.name 3(601 class list) accuracy is so bad. At the images and videos all classes are generalized. Bee like animal, horse like enimal cars like vehicles and many other objects are not recognized. If you have experience with yolo, please advise me what to do?