Resolve as in the next day showing thumbnails the day where there were none is still without

Mine seems to work now not sure why it just seemed to resolve the next day, bit worried it will happen again as there doesn’t seem a clear reason why it occurs or what helps

My C310 camera works well. However, today most of the thumbnail images under 'Activity' on the Playback tab are bot showing. Only 1 thumbnail there now. All detection videos are still there and able...