Slingshot Alien Twister 4'8" won't stay in the pocket

For Christmas, I got a Slingshot Alien Twister 4'8" from blemboards. It was a good deal at less than $200. I didn't need it, I just wanted to add a board to my quiver and it was a steal. So I took it out last weekend, and I simply could not keep it in the pocket - at all. Even with vigorous pumping, I just washed out the back. I'm 5'8 and 190 lbs. I ride a Carbon Thruster, a Doum Skim, and a LF Noserider. I am an intermediate rider and normally have zero problem staying in the pocket on any adult board.

So, my question - is this board defective in some way or is just not for me? Anyone got any experience with it? I spent about 45 minutes over 2 sessions trying to ride with the rope and get the feel, but it just won't stay in the wake.

What kind of fin set up are you using? Looks like it has a quad setup and comes with all 4 fins.
If you have all 4 fins in I bet that's dragging it a bunch. I'd try it with just the front fins in.