rozboonDespite your assertion that the forward pressure is set correctly, the forward pressure probably isn't set correctly.
Setting it just right on an FKS/Pivot is a bit of a black art, the little tab on the heel won't always line up perfectly depending on boot brand and how worn the heel and toe lugs are.
Disclaimer: Adjusting your own bindings will probably cause your legs to evaporate in a fine mist of shattered bone and ruined ACLs.
With that out of the way, I would tighten both sides of the forward pressure adjustment by a couple of clicks and see if that helps.
This. The indicator at the rear of the base plate barely moves with adjustment of the arms. The practical test is to set the forward pressure so that when the heel piece lever is slowly raised (with boot installed) it gets to half-way and then it snaps up. Once the boot is fully locked in there shouldn’t be any lateral movement at the heel. Also, with the boot in the binding, grab the dildo part and rotate/pivot it. Increase the forward pressure until you no longer get significant rotation/play when doing this.