Can you try driving it without the pump connected ?
To prove the alignment is right.
I'll assume RF & LF caster differ slightly to accommodate road crown.
Ran about +5.5 caster (tubular upper arms) & just under -1 camber on my 512 Duster (manual steering, which was fine) and it had no issues.
I hate chasing the steering when driving.
I'm thinking that if the pressure's too high, that's what's happening: constantly adjusting input.
Another thing to try is operate the steering wheel 1-handed at the bottom, as light a touch as possible, to make sure it's not a driver-input issue.
But yeah, if I had to guess, maybe too much PSI; but that's only a guess.