The newly added ICV (P) has a large turret deadzone in the rear that prevents turret traverse in the rear. This seems to be due to the fact that the devs copied the traverse of the RCV (P), which has optics in the rear that blocks traverse in the back. The ICV does not have the optics and should not have the same problem at all. In tests drives, the issue is not faced when the vehicle is in “Reference”, but the deadzone reappears when placed at “current”. My ICV is currently mostly stock with only Parts and FPE researched, so there might be a module research that removes the bug.
My original reddit post about the issue
theres a dozen bug reports ranging from a month old to barely a week old, still aint fixed.