It cannot request and receive EDID data when the monitor is powered off since the monitor must be active to relay that data. It can sense that the cable is connected. As soon as the monitor is powered on the PC requests & gets the EDID data so it can configure the ‘new’ device just detected.
This process can interfere with earlier configured connections for that monitor so it does not surprise me that the OP is seeing what he terms as ‘weird behavior’. After all the way he powers it off and on is not what most users would consider normal.