Hi Gary,
I had an issue with Brasero hanging when burning audio CDs in 18.04. The problem I found was that I would start the process to Brasero to burn an Audio CD, it was all OK until I hit the ‘Burn’ button. At that point Brasero would just hang. I found this bug which provided a work around https://bugs.launchpad.net/ubuntu/+source/brasero/+bug/1770502
The work around was, open a terminal and type:
sudo chmod 4711 /usr/bin/cdrdao
sudo chmod 4711 /usr/bin/wodim
sudo chmod 0755 /user/bin/growisfs
Your problem could be related, would be worth giving this a try.
I would appreciate it If someone in the community could explain how packages are given system privileges to access hardware, perhaps the bug isn’t directed correctly? There has been no progress with this bug for more than a year and a half and it's disappointing our disto can’t burn audio CDs out of the box.