Yes, mine does the same thing:
1) I enabled developer options to make sure the "stay awake" feature was not enabled and it was not.
2) I have already plugged in while off. Turned itself on while plugged I turned it off, it still turns itself back on.
3) Nothing in developer options was been messed with or turned on.
4) No other phone I've ever had has insisted on being on while being wall charged.
5) The phone will charge while off only while connected to the computer's usb.
6) I have the international version of the LG G4 bought on Amazon.com.
7) It is a bit of a pain in the a**
