I see I am a little late to the party on this one, but since I have the Apeks version of this BCD (Black Ice) I figure I should throw in my two cents. I know this exact problem you’re talking about because I experience it to this day and continue to compensate for it myself. Colliam7 is entirely right about this being a better BCD for diving doubles due to the lift and subsequent size of the bladder required for that lift.
I began noticing when diving with this BCD that I would struggle to stay streamlined and with my front side parallel to the floor, often rolling to one side or the other. To compensate for this requires having your weight well trimmed and distributed, having good buoyancy skills, and great comfort in the water. To compensate I just do a quick roll to the opposite side that I am being pulled to to shift the air pocket in the bladder and redistribute it a bit better. When you do this, you should hear the air shift in the bladder and when you get good at it, this issues tends to not be a worry because it just becomes second nature.