Good thought. What vanes were you shooting before? There shouldn't be any difference in spine, if you're shooting the same spine.

The only other thing that comes to mind is that if your arrows were at the upper end of the spine range, then possibly the rigging on the bow has crept. The draw length and poundage go up and maybe the arrows are slightly underspined. Twisting up the string and cables to put the bow in spec might be the answer.

I'd do some powder testing to check for clearance. If this is OK then try dropping the poundage of the bow a turn or two and see if they fly better. This will be a check for spine. If it ends up being spine then you got several choices. Leave the poundage a little lower, buy stiffer arrows, or go back to the old arrrows and see if that works.