Just for fun before you modify, try a different (higher) hold on the pistol and get as much palm flesh "behind" the grip as is comfortable. I wouldn't have believed it if I hadn't experimented with the advice I found in some reliable old standard texts on handgun shooting (Askins, Skelton...) how much the POI changes with slight changes in gription. But in addition to making changes, if you find success, remember those changes and practice to develop consistency. The rifle shooters who argue the importance of consistency, have nothing on us handgunners.
Knowing what I know now I am certain that I sold handguns that I thought were inaccurate, but were very likely not.
Ed