Support

As per https://www.akeeba.com/documentation/akeeba-backup-joomla/configuration.html#quota-management you need to remember three very important points:

• Quota management is applied per backup profile.
• Quota management is applied against backup records, not what is stored on your server or remote storage.
• By default, quota management only applies to files stored on your web server. To enable management of remotely stored files you need to set "Enable Remote Quotas" to Yes.

The log files you sent me are unusable because you've set the Log Level to Errors Only. As a result, the log files are completely empty since no backup error occurred. Please check the points made above and you will be able to solve your problem.

I believe that you have not checked the Enable Remote Quotas in your backup profile. I am saying that based on experience helping other people with the same problem.

For what it's worth, I positively know that the remote file quotas work as I am using them on all of my sites, i.e. my production sites (including this one here), my testing sites, and my development sites. I am using quotas daily, both for locally stored files (dev sites) and for remotely stored files (production, testing, and dev sites). Especially with test and dev sites, I am taking several dozen backups every day. If quotas didn't work I'd have noticed since I am very limited on space on the target disk where the backups end up.