Small question on the usb Pi4 CR-6

on the raspberry Pi4 8GB model, is there a way to turn off power going over the USB? I have noticed that with the new Creality CR-6 se when i shut it off, it pulls just enough power from the Pi that it tries to stay on, enough that even the LCD screen will even stay lit, fans stay on....... i find it VERY strange. if I unplug the usb while power is off it shuts down, but then only plugging in the USB it will boot off of that..... that does not seam like a good thing. any advice.

You can put some tape over the 5V pin of your usb connector.
Then your printer can't power from your pi and this shouldn't happen again even if you power on your pi first.

(pin 1 is 5V)

I would really like to know how you got the Pi4 8gb working. I had to buy a 4gb version just to get it to boot...