Random keyboard input on shutdown will power up Macbook Pro
The best way to shut down your Mac is to choose Shut Down from the Apple () menu.
Just as your Mac follows a startup process after it turns on, it follows a shutdown process before it turns off. That process includes automatically quitting all open apps and logging out of your macOS user account. 
If your Mac doesn't shut down, try Force Quit to close any apps that aren't responding. If that doesn't work, press and hold the power button until the Mac turns off.

Ok, here are the 3 power button options 


Press the power button (briefly) to turn (off or on) the Mac or wake from sleep. Also called the normal method.
Press and hold the power button for 5 seconds or longer without lifting to force your Mac to turn off. Also called brutal method. Do not use frequently. It will not wake up after by any keyboard combination until you press the power button.
Press and hold power button for 1.5 seconds to get the turn off dialog. This dialog will ask if you want to restart, shutdown or put the Mac to sleep, this is the same as you would do with click under the Apple Icon (top left)




Other stuff...
You have a app called FOLX 5 Downloader that is preventing your Mac to Sleep. Quit that program, if it is still running, Open Activity Monitor find it and Quit it. You can also find it under its PID number pid 6959

Here are some instructions how to deal with the T2 chip.