It takes a noticeably longer time to restart or shutdown with the new drivers. As soon as 19.5.1 is uninstalled, the problem goes away. I reverted back to 19.4.3.
Win 10 - 1809
Definitely seems something internal to the card, because Windows shutdowns down normally, then it takes inordinate amount of time at black screen. Can even see the monitor report signal lost.
Startup is normal.
If no one else has the problem, I might try reinstalling or using DDU to wipe amd drivers.