Stephen,
Sorry about the poorly formed message. From my Google research on the topic of shutdown failures on Ubuntu 18.04, it appears there are no longer any shutdown messages in the kernel.log or other logs. I was hoping someone could point me in another direction to diagnose the problem, but I did not frame my question very well.
Today, after a lot of googling today, I stumbled upon a way to diagnose the problem...hit escape at the Ubuntu splash screen to see what is being printed to the console as shutdown progresses! It seems my system is waiting for mysql to shutdown. So now I have something to work on!
Thanks,
Mark