[Nottingham] Odd thing with DVDs

[Jason Irwin]

I've been noticing that about every second cover DVD from LXF isn't
recognise (e.g. the latest one from LXF 170 does work).

when I insert a working LXF disc (e.g. 169) I see this from "dmesg | tail":
[20648.469260] ISO 9660 Extensions: Microsoft Joliet Level 3
[20648.521012] ISO 9660 Extensions: RRIP_1991A

And when I eject:
[20684.406735] VFS: busy inodes on changed media or resized disk sr0

All looks as-to-be-expected

When I insert a non-working disc...nada.  And I know the disc works as
I've tried it elsewhere.

Where does one begin with diagnosing why the disc isn't getting picked up?

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