AJ, welcome to the Crew!
Yes, the 150 does point higher than the 140 but I would also agree with Allan that it is possibly that you were riding with too much back foot pressure. The Mako relies on its upwind rail to grab the water and not the fins so by parking on your back foot - like you have to with all other kiteboards on the market - you lose the ability to bite and gain traction. This is really important when turning too. Drive your weight forward through the turn like a snowboard, don’t sit on the back foot.
Good luck!
John Z