@Ross_Daniel found a bug in rigbits.eye_rigger. I can confirm it on mGear 3.0.3
eye_R_upMid_ctl.hTracking and eye_R_lowMid_ctl.hTracking are connected backwards, and/or the range of the attribute should be negative instead of positive.
So when rotating the eyes, the hTracking is moving sideways in the opposite direction.
This occurs on the right eye only.
vTracking is fine.