Uncommanded pitch on engine spool up

I am getting uncommanded pitch up when I apply power on the ground and would like to ask if someone can help solve this by looking at a log and parameter file.

The uncommanded pitch occurs when battery current increases and below is a graph of Pitch (red), Current (Blue) and DesPitch (Green).

The setup is a custom quad with a Kore Board and Orange Cube running Arducopter V4.o.7. A 22,000 mAh battery is mounted on top of the frame and about 50mm above the cube. The internal compass has been disabled and a Here3 GPS/Compass is the primary compass. I have done a Compass/Motor Calibration and getting an interference of <5%.

The motors are 100% mounted in the correct order and are spinning the correct way!

The log is of the quad sitting on the ground and power applied (twice) then reduced. The quad pitches up and would topple over if further power was applied.

I’m obviously getting interference from the battery current but would like to know how it is affecting the pitch.

Any help would be appreciated!!!