your problem it has to do with the hopup bucking not coming into enough contact with the bb, which is resulting in not enough backspin.
If your bb's are too heavy, you need more backspin. You should be using 0.2 or 0.25 bb's in this gun.
If you are using those bb's, then either you need a new bucking, or the nub isnt big enough, so when fully adjusted, it isnt pushing far enough into the hop up. Theres also a slight chance that they forgot to put the nub in the hopup unit. I doubt it though.
Remove your barrel and hopup from the gun. Look down the barrel with the hop up fully adjusted and see if there is a piece of rubber pushing into the barrel. That is what gives backspin. If this nub isnt pushing in very far, then thats why you have no backspin. If it is and u still have problems, then try a new bucking and nub.