Is Battery Current Reading Broken?

I have seen this question worded in various ways in the forum, but no definite answer on measuring current from the power module, right out of the box. In my case, Voltage is reported correctly, but Current is always zero (0).What’s the consensus?

The F550 frame uses a PCB to distribute power to the ESCs, so I soldered the end of the power module that pairs with the NAVIO2 power connector to the pads (+) (-).

Two LiPos in parallel are connected to the other end. Does it matter which way the juice is flowing? Should I flip sides?

NAVIO2
RPI3
OS: emlid-raspbian-20170323.img
ArduPilot: APM:Copter V3.4.6

Copter Power Source:
two (2) 3200mAh 4S LiPos wired in parallel