OK, I set up an octopi server for my anycubic i3 mega and Ender3 v2 a couple of days ago. I have noticed the raspberry is powering the display on the Ender 3? I only noticed it as when I set up the printer was running but yesterday I tried to print a part and it kept rebooting after the print was selected from the sd. I thought turn it off and on again but it was already off.
Unplugging the usb cable from the pi or printer closes down the display. Turning off the pi power works the same. Clearly the 5v USB from the pi is powering the ender3 main board
You can download this in OctoPrint's System Information dialog ... no bundle, no support!)
OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible</small
Running latest octoprint 0.18
Pi4 b 4mb
Stock ender 3 firmware