Automated backup doesn't skip hidden files despite setting

Moodle 3.8+

The automated backup seems to insist on backing it all up, even if 'Skip Hidden' option is ticked in the settings. Is there some trick I've been missing all these years?


In this particular case I've got around 90 - 100 hidden courses, and yes, they all appear in the backup directory we've specified... so what have I missed??

Thanks in advance!