Air draws 40mA current after shutdown

[SidDelicious]

I have a NanoPi Neo Air running the FriendlyCore Xenial 3.4.39_20171102 image. The board continues to draw about 40mA after "shutdown -P now". I've measured this both with a USB power meter connected to a 3.0 port, and an external power supply with an inline multimeter. As far as I can tell the WL_REG_ON/BT_RST_N pins on the AP6212 are low, so it seems like Wi-Fi/Bluetooth shouldn't be the problem. Anyone know the source of the draw?

Thank you

[SidDelicious]

I noticed that if I interrupt u-boot and issue the "shutdown" command, the current drops to around 11mA.

The 3.3 and 5V pins also stay live after "shutdown -P now". Is FriendlyCore is leaving hardware powered after shutdown by design?