If the backup comes from the recorder, check if you can view the recordings on the recorder. If they can not be viewed from the recorder either, chances are there is something wrong with the configuration.
For example, there can be a misconfiguration in the recording spaces. If at some point there has been changes to the settings, this may cause old recording files to remain behind. Since these exist, the database doesn't clear itself correctly. As a result it can show recent recordings when in reality the last actual recording can be from a longer time ago. Fixing this requires regeneration of the database and removal of the overflowing recording files. Since these are always unique cases, please contact our support for more instructions.
If the recording spaces are set up correctly and there are no system errors, the issue is most likely with the motion detection settings. The issue can also be that the wrong camera type has been chosen for the camera when adding it, which causes it to use the wrong format.