I have a My Cloud EX2 Ultra that I use exclusively for backup purposes.
I work on an external HD drive, that regularily conect via USB to the NAS for backup.
No problem with the OS3, but after updating to OS5, the job fails every time.
I’ve tried uninstalling the “USB backups” app and re-installing, but it did none.
I’ve tried also to delete the old backup job and create a new one, but fails again.
Here’s the job I’ve been using for years, that now it’s useless: