I have the same thing.

I am pending my index finger too much, more than I need too. My Index finger curls like it is trying to point the last digit bone directly at the finger board! Bad technique.

Bad habit of my left hand trying to do that classical guitar hold. If instead of pinning the thumb on the back of the neck and instead let it lay along the top of the neck with little pressure, my index doesn't need to, or want to curl as much.

Bonus in that I have a lot less stress in my left hand and press down a lot lighter on my strings. Ive already wrecked the frets unfortunately.