According to the log file the file was deleted:
DEBUG |181202 23:24:02|Deleting already processed file <root>/backup/site-www.oukside.com-20181203-062001.zip
Please note that only the file from the backup currently being taken
will be removed. Any older / leftover files will NOT
If the file mentioned in a "Deleting already processed file" line has not been deleted from your server please contact your host. Akeeba Backup uses PHP's unlink() function to delete files. It's the same function Joomla! itself uses to delete temporary, cache, installation etc files. If this function does not work properly it's something your host should know and fix. We have no further control over the matter.
Finally, I'd like to note that you are the only person who is reporting this issue. If it was really a bug for such a fundamental issue we'd have definitely received reports for it, let alone experienced it ourselves on our own production sites. This tells me that you are either looking at the wrong file (mistakes happen), expect a file from an earlier
backup to be removed (it won't; you'd have to do it manually) or something is wrong with your hosting environment. I hope this helps you figure out which of these issues outside our control results in the effects you observed.