Maintenance Mode after user_usage_report update

Nextcloud version : 19.0.4
Operating system and version : Ubuntu 20.04
Server: Virtual machine on VirtaulBox - can do Snapshots for backup and debugging

Problem:
After clicking “update” (without taking a snapshot from the VM) for the “user_usage_report” app to the last version on the nextcloud website the nextcloud make no progress, only shows updating… After 20min and a manual refresh of the nextcloud website, the site was in maintenance mode.

  • the config/config.php shows ‘maintenance’ => false,
  • trying “sudo -u www-data php occ maintenance:mode --off” shows “Maintenance mode already disabled” and does not help
  • there are no “*.step” files for the updater in the whole nc dircetory
  • disable “user_usage_report” does not help
  • update the nextcloud to 19.0.9 via “sudo -u www-data php updater/updater.phar” does not help
  • “sudo -u www-data php occ maintenance:repair” does not help
  • “sudo -u www-data php occ maintenance:mimetype:update-db” and “sudo -u www-data php occ maintenance:mimetype:update-js” does not help
  • “sudo -u www-data php occ integrity:check-core” passed
  • “sudo -u www-data php occ log:watch” shows only “Debug serverDI The requested alias “PreviewManager” is depreacted. Please request “OCP\IPreview” directly”

I tryed a lot more combinations of occ commands (including to restore the snapshot after updating the app) which i could find on the internet and sounded plausible but it does not help.

I think that the maintenance mode is somehow still activated in the database, unfortunately I don’t know where to look.

to explain my assumption with the database: I compared the last changes to the files after the app update and couldn’t identify any relevant files that could trigger the maintenance mode