I just had to replace my Warchal Amber A after 2 months because it started to unravel roughly at the D position. I've had this problem several times with the Dominant A and always in roughly the same spot. I believe I had the same problem with Pirastro Evah Pirazzi A strings. I didn't have the problem with Olives or Eudoxas. So I am thinking that maybe I am doing something, the way I shift to second and third position might have something to do with it. Any diagnoses?
How many hours daily? Most of the modern strings do not last more than 200 hours.
That's the exact spot where strings first start to unravel for almost everyone. It's the most-used point on the string.
Part of that is because the winding is probably aluminum, a soft metal. And maybe friction; do you hold the string down to the wood when shifting positions, or release the pressure when moving. I tried the Warchal steel "Russian" A for the first time just last night - very promising.
Or replace the wound A with a plain gut A. No aluminum winding to wear out so it will last longer, and give a better sound.
Funny my Tonica A string is also unravelling at the D fingering location!
What about checking the state of your fingernails. Are they trimmed closely enough?