I have been having a similar problem. I found that my weak hand grip was too loose. When I made a conscious effort to correct this, the groups moved back. As soon as I went back to auto pilot everything went left again. Could this be a sign of another problem? I also tried adjusting my trigger finger location to no avail.
I started using a grip exerciser while driving around town. Twice as any repetitions on the weak have as on the strong. The groups are moving over on their own.
I was surprised at how much difference there is between strong and week hand (at least in my case).