Why is the motor phase current like this in six-step BLDC drive?
If this is trapezoidal drive, you appear to be turning on the gate of one of the "off" phases.  This may be due to the reverse transfer capacitance which is quite high with all of those MOSFETs in parallel, or possibly you are drawing enough current in your inductive current path on board board to pull down the source with respect to some of the gates.

I would start by reducing the value of the 10K pull down resistor on the gate to 1K and see if this improves your problem - this may work if it is the drain-to-gate capacitance turning the FET on.  In any case, measure the gate voltage on the FETs during their off period with respect to the source.