nvds_obj_enc_process save wrong source frame image

[challengesll]

Hello, Sir/Madam
I am running the deepsteam-parallel_infer_app in my job now. I want to save the image on Jetson platform.
When I set up multiple steams, I found nvds_obj_enc_process has problem. It saved the wrong source image:
When I execute the Nvds_obj_enc_process function, the frame image saved is the wrong source frame image. I want to know what operations the Nvds_obj_enc_process function performs. Is it the offset error of the current frame that causes the acquired frame image to be incorrect or what is the reason?