Backup (Cron.class.php, func add) do not add backup schedule into asterisk crontab

Hello, I have FreePBX 13.0.187 host with Backup module 13.0.26
Backup module stopped to write backups (local storage). Tested with default backup.
Backup information appears:

  • in mysql db
  • backup.php
  • utility.function.php
  • Cron.class.php
    In Cron.class.php var_dump shows cron job command (@daily ID=freepbx_backup_1 /var/lib/asterisk/bin/backup.php --id=1) the last time in function “add”, before "foreach ($addArray as $add) {"
    I see that modification time of /var/spool/cron/asterisk changes every time when i modify and save Backup schedule (daily to weekly and back). But job @daily ID=freepbx_backup_1 /var/lib/asterisk/bin/backup.php --id=1 doesn’t appears inside.
    I tried to remove Backups and create new one, but unsuccessfully (manual run of Backup works correctly).

I have another host with a similar setup, all works correctly too.
Any ideas what happens?

There is a file /tmp/cron.log that may contain the error?

Often your crontab file is corrupt.

No, i have no /tmp/cron.log, i just have a blank /tmp/cron.error, modified 3 month ago.
Also i have no errors in /var/log/cron

I changed backup schedule from daily to weekly on another working FreePBX host, cronjob disappeared from crontab and do not appears anymore. Help.

Seems like this issue relates to FREEPBX-13054 and requires upgrade of FreePBX Framework (not Backup module).