Where is Metadata stored for existing recordings after npvr.db3 purges old shows?

[Comp2TV]

Where is Metadata stored for existing recordings after npvr.db3 purges old shows?

I think the software is working correctly, but I want to know so I can avoid losing metadata.

I am set for EPG updates at 2:30 a.m., but my computer is usually off at night. Still, the npvr.db3 is adding new shows and purging old shows (less than a day old) regularly. I have used a SQLite viewer to check this.
Once every several days, I click on "Export Recordings" in Settings to get metadata save to recording-backup.xml for my recordings that I haven't removed. That file rarely updates unless I click Export Recordings. This export has occasionally missed metadata for some recordings, I maybe deleted something to have caused that.
I have set <StoreSeparateMetadataXml>true</StoreSeparateMetadataXml> in config.xml.
I get a XML file with metadata for each recording, but they are missing cast and crew members which will show up in recording-backup.xml .

I am running NextPVR 4.2.3(181112) on Windows 10 Pro 64bit (Version 1803).
I am not running anything with NextPVR like Kodi or Plex. I am just manually moving recordings and metadata.
I have heard of NextPVR archiving reature but have not used it.

[sub]

You probably havn't noticed a copy of the show metadata stored in the SCHEDULED_RECORDING table in npvr.db3. That is where data is stored and loaded by the application.

The recording-backup.xml, or <StoreSeparateMetadataXml> .xml files, are just a convenience for reimporting recording information if the user has some unexpected problem and needs to reimport data.