I have a HP Envy x360 cp15-0010ur on AMD Ryzen 7 2700u with Vega 10 GPU. OS: Linux Mint 19.3. After turning off, the screen goes blank and the laptop continues to work. syslog does not show anything unusual. If you need any logs - write, I am ready to send. It is known that there is no such problem on the 5.0.0-32 kernel.
This is a pretty old bug, but do you still have this hardware and can you still reproduce it with a modern 6.1.5 kernel?