why insightface cannot detect face in vggface2 dataset

Using this api, 480K images in vggface2-hq cannot be detected, which is used to train a face recognition model.
```
self.app = FaceAnalysis(
name='antelopev2',
# name='buffalo_l',
root=os.path.join(cache_dir, "insightface_models"),
providers=providers
)
self.app.prepare(ctx_id=0, det_size=(640, 640))

image_bgr = cv2.imread('xxxx')
face_info = self.app.get(image_bgr)
```
How can I resolve this problem? Anyone can help?