Preliminary 0.9.0 Boron LTE current consumption in sleep modes measurements

Hey,
Ending up with a peculiar problem here. In sleep mode, I’m going down to a current draw of 1.2mA when I’m using a LiPo battery, whereas when I’m using the USB, the current draw fluctuates around 13-16 mA. I am using the same code. Also, when I power through USB (either computer or 4xAA battery pack), the CHG LED continuously flickers yellow when there isn’t a LiPo connected (when a LiPo is connected, it charges the LiPo and stays a steady yellow).
Anybody know why USB might be drawing far more current in sleep?

SYSTEM_MODE (MANUAL)
..
void loop()
{
Cellular.on();
Cellular.connect();
waitUntil(Cellular.ready);
Particle.connect();
waitUntil(Particle.connected);
..
Particle.disconnect();
waitUntil(Particle.disconnected);
Cellular.off();
delay(6000);

System.sleep(D1, RISING, 600);   
}