SGIE not inference on every PGIE object with multi cameras

[yuweiw]

1. Could you attach the pipeline graph by referring to our FAQ.
2. What do you mean PGIE Objects that has no SGIE object?
3. From your description, this problem should have nothing to do with deepstream-parallel-infer-app and the source format. Can you use our simpler demo like deepstream-test2 and a local file source to reproduce the problem?