The Hikvision NetHDD configuration / 'format' creates a fixed set of placeholder folders and files, and some indexes to the content held within these files. Even when video is being recorded, you will not see any additional or deleted .mp4 files, but the content within will have changed, as will the index that keeps track of what is where. Your screenshots do not show the storage schedule and event configurations for the camera. Unless you use a 3rd-party tool to extract the video via the index files that track them - you need to use the camera's own 'mini NVR' facilities under the Playback menu. Depending on whether you have configured the camera to do continuous or event-driven recording, you will see either a continuous blue line, or periodic red markers for motion / event recording. I hope that makes sense.