You may well have an arrow spine problem. I agree with those who say you should probably be shooting .500 spine arrows cut back to 30-31” if you want to continue shooting 125 grain points. Even then, you may find that 145 grain points work better, and you should keep your mind open to that.
However, spine is not what is causing your occasional left misses, at least not on a fundamental level. Spine errors can make arrows more touchy, and react more to form errors than well tuned arrows would.
But you are almost certainly doing something to cause these occasional left misses. You are changing something you are doing, or not doing, when your arrows are grouping. You didn't mention whether you are a RH or LH shooter, and the causes of left misses can be very different for each.
These are the most common causes of left misses for a RH shooter:
Not coming to a consistent anchor: movement of the anchor by 1/8” on the face results in a 6” change in POI on a target 20 yards away.
Not coming to full draw, which leads to the drawing elbow not being behind the arrow: the arrow will tend to follow the direction the drawing forearm is pointing at the time of release.
Shoulders not in alignment: the arrow will tend to fly in the direction the shoulders are pointing at the time of release.
Torquing the bow or the string, as was mentioned.
Arrow not beneath the dominant eye. Have you checked your eye dominance? You can force yourself to aim with your non-dominant eye, but your dominant eye will occasionally take over. Or, this could be a subset of an anchor problem. One anchor could put the arrow under the dominant eye, while an anchor 1/8” away, or tilting your head inconsistently, could put the arrow to the right of the dominant eye, causing occasional left misses.
String grip problem: having an inconsistent hook, or a hook that relaxes the longer you hold it, could cause occasional left misses.
Not transferring at full draw to the hold position. This really is just another way of saying that your shoulders are pointing to the left of the target at the point of release, but more specifically that you are not transferring the weight of the hold from your arm muscles to your back muscles by rotating your shoulders into correct alignment as you expand.
There are other potential form issues, of course, but these are the ones I can think of off the top of my head that would be most likely to cause occasional left misses.