Audio CDs and disc images may not mount on a computer running a version of Mac OS X 10.3. Audio CDs do not appear when you insert them into the drive. Other CDs and DVDs seem to work normally.
You may also notice that disc images do not appear, and double-clicking the disk image results in an error code -536870208.
The solution?
Update to Mac OS X 10.3.2 or later.
And people complain about bugs in Catalina!