I have the exact same issue, tried your troubleshooting methods. After which gave up and created a ticket and RMA'd the chip, from what Nick had told me its an "interesting" issue hence prompting me to send the chip instead of going back to vendor. On the other hand it seems to drain and heats up on idle, not entirely sure if the batteries are killed as I've tested the battery on other mod which worked fine. Higher chance the chip's capacitors are doing something funky within which we'll not know unless full component and layout is given. (Something not advisable to do for a company)