Depending on how your arrow shelf is cut, they could be too stiff. Axis arrows are about half the diameter of woodies so their center sits closer to the center of the bow compared to wood. That means they can be heavier spined. Or, looked at another way, using thicker arrows has the same effect as building out the side plate, which requires less spine.
Of course, form (plucking) and brace height (too low) can also cause fishtailing, but too much spine is also often a culprit. Could up the point weight a bit and see what happens. Good luck.