Same problem here on 2022 NVR model:
DS-2CD2047G2-L connected on DS-7608NXI-K2 Event Playback starts 5 to 10 seconds after the target is gone!!!!! (1920x1080, variable bitrate, 3072kbps, 25fps)
On iVMS-4200 Event Playback works exactly as you set pre-record and post-record. On NVR playback...