I am having trouble picturing you issue here. So, you are cruising down the slope and need to make a really quick turn onto a cat track (trail) to your left which sounds like that is a heelside turn for you? When you do this, is the board just skidding sideways still going down the hill that you are on instead of actually making the turn?
Correct me if I am wrong, but I am going to go with this scenario for now. Many things could be causing this issue and ultimately your technique (or changes to it) will improve your situation for the most part. The surface conditions will play a huge role here. If it is hard and icy, any board is going to have some trouble, but a banana magic (I assume full rocker???) will have more difficulty in setting an edge and carving your turn. You simply could be going too fast to negotiate the turn and need to plan ahead a little sooner so that you can ease into the turn a little more. I am not familiar with your board so I am making some assumptions here. In general though, not every board can handle the same terrain equally and while your friends are having no issues, your board may require you to adapt your technique a bit.
In general, with any board, getting more dynamic in your riding and having more flex in your lower body (especially in your heelside turns) will allow you to keep your edge set while in a hard turn. Learning to carve better is going to be invaluable to you as a rider and this scenario here is a great example of how good carving skills can pay off. A skidded turn is just not going to be as controllable in this situation as setting into a good dynamic carve to get that board to go where you want it. Additionally, you might not be on the ideal board for the terrain and the conditions.
I wish I was more familiar with the exact nature of your board and had ridden it to be able to offer you more.
If i recall correctly, i read somewhere that you bought a new split board.. i hear that those have the same problem, like they dont catch the edge as fast, can i have your oppinion? i am interested in buying one of those...
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