Apple USB Superdrive doesn't read DVD-RW video disks
I've just got a new iMac (Retina 4K, 21.5-inch, 2019) which is running OS 10.14.5 along with an external Apple USB Superdrive.
I have a large collection of videos on DVD, some purchased but some recorded on a Toshiba RDXV59DTKB video player/recorder.
I can play commercial DVD recordings from the Apple USB Superdrive and DVD-R and DVD+R disks I recorded myself.
However, when I load a DVD-RW, no files or folders show in the Finder and no applications will play the disk. And yes, they have been finalised.
There are videos on these disks - I can load the disk in to the Toshiba and play the video. I can also dub the videos back to the Toshiba HDD and then re-record them back to a DVD-R and play that in the Superdrive. So, I can still get at the videos on the iMac with the Superdrive but it is a hassle dubbing back the the HDD and then re-recording onto a DVD-R.
Suggestions please to getting the DVD-RW disks working in the Superdrive?
iMac 21.5", 10.14