OK. That makes some sense. So what I think you're seeing is that your temp is likely filling up due to a failed backup which may be causing your issue.
I would encourage you to get in touch with Support to have them review your setup, but this all may be caused by your archiveconfig settings.
If you go into the manager menu and type archiveconfig, this command backs up the database files. If you've previously set up the backup location to somewhere that isn't reachable or has been moved/deleted the LEM may be unable to offload the backup and may be storing the files internally and causing issues.
You'll want to check, test and verify your archiveconfig settings and/or have Support check this with you.
You can find some additional information about the settings below, but I didn't find a KB article discussing the issue I've described above: