This is normal and why you
This is normal and why you should never leave the key On for any length of time. The power steering, brakes and all 12V systems are being powered through the DC/DC converter by the HV battery with the key in the ACC position. If you must keep the key in the ACC position for a long period of time, I would keep the vehicle in "Park" in EV so the engine will restart at a 40% SoC and shutdown at 42% SoC. This will keep the entire system charged and protect the batteries from draining below their minimum limits.