Yast restoration fails with multi volume backup

I have been running regular full system backups with Yast backup. The backups are stored on a 500GB usb drive and the backups are broken into 4.7GB volumes so that they can be burned to a DVD if needed.

Last night, I decided to test backup restore in yast. It started ok and then failed with a message that the archive was not complete.

I then unarchived manually with tar and got the same error until I realised the -M option has to be applied for multi volume archives.

Using the appropriate options I was able to unarchive manually with tar successfully manually entering the filename of each volume when prompted.

Why doesn’t yast restore do this automatically?