I discovered a problem with the backup solution described at https://fusionpbx-docs.readthedocs.io/en/latest/getting_started/backup.html#crontab for crontab. The files in /etc/cron.daily will not run if they have an extension. Or at least they won't run with and extension of .sh, which means that fusion-backup.sh and fusion-maintenance.sh will not run. When I removed the .sh they worked correctly. Since my Debian installation is pretty plain vanilla I assume I didn't do anything to cause this.