HELP! CDJ 800 MK2 won't read Traktor Scratch CDs

My CDJ used to work fine - but now all of a sudden will not read Traktor Scratch CDs. After inserting the disc, it will attempt to read for a few seconds and then directly eject the disc.

The CDJ reads CD-R discs completely fine.

There is no error code displayed on the CDJ and it's running the latest firmware.