I think it has something to do with the export
It only export the image minus any bits that are non-image. The info is recorded in the hard drive and i can play it back offline with time stamp using HDD Viewer from dlink. It sucks though that the time stamp is not embedded in the image itself which means if i have to share video with others, it means i have to bring the hard drive and a computer with hdd viewer installed or the other party have to install hdd viewer in their computer.
Btw, i tried the export function using the hdd viewer, the feature is there but its either non-functional or not working. Snapshot in hdd viewer works but same issue, no time stamp.