It's a combination of torque, concentration, and failure to do a lot of things consistently. At this stage of the game, it is best dealt with by just enjoying shooting for a while until you get used to your new bow and the movements required to shoot. You should focus on increasing your awareness of what's going on when you shoot an arrow, without spending a lot of time making judgements about it. As you become more aware of what you're doing, you will make a lot of necessary corrections without having to consciously decide to do anything. Frequently, we think we know what makes one arrow go one way and another arrow go a different way, but we're wrong and making a conscious correction just makes things worse.
After you become comfortable with your new setup, look around for a class or send a video in for Arne to evaluate, and then you can start tweaking your form. It's always easier for someone else to see what you need to change than trying to figure it out yourself, although that can work too; it just takes longer.