Issue Scheduled backups stopped running

[shogunswb]

Plesk 18.0.28 update 3
CentOS Linux 7.8.2003

I have daily scheduled backups running at 01:15 in the morning but the last scheduled backup to run was on the 2nd July before the 18.0.28 Update 1 ran which may or may not be coincidental.
I have checked for stuck jobs of which there were none, I have checked the plesk-backup-manager-task & its permissions which were fine but deleted & recreated with the correct permissions, rebooted the server, changed the permitters of the backup ie time, local storage only, remote storage only, what it backs up etc but nothing seems to kick off the backup.
Manual backups run fine.

When I run:
grep backupmng /var/log/cron via ssh

i get

Jul 19 03:37:01 anim CROND[21689]: (root) CMD ([ -x /usr/local/psa/admin/sbin/backupmng ] && /usr/local/psa/admin/sbin/backupmng >/dev/null 2>&1)

& this seems to run every 15 minutes but I have to admit I have no idea what it means.

 

[IgorG]

Try to find a reason in backup logs in /var/log/plesk/PMM/

 

[shogunswb]

It would appear that there wasn't enough room on external storage (error 13) which there should have been but I have since cleared out some of the older backup jobs so there is plenty of room. It's now not showing an error code but from my limited knowledge of log files it would appear that the backup job is starting & collating all the data but just not backing it up physically.
The other thing is that up until the 16th July the job was starting at 01:22 but when I was trouble shooting I changed the time to 09:15. I have since changed the time the backup runs back to 01:15 but today it didn't run until 09:00.

 

[shogunswb]

I have updated to the latest Plesk version 18.0.29 this morning but still unable to get scheduled backups to run.
I have also noticed that it takes a relatively long time 10 seconds or so to open backup manager & I have seen that this is caused by external storage issues logging in etc but even if I disable external storage (Google Drive) it still takes 10 seconds for backup manager to open.
I can still run manual backups fine & cannot see any errors in var/log/plesk/PMM/, cron is definitely working, no stuck jobs.
I could really do with getting this fixed.
Thanks