Is your car stock height or lowered now? I suspect lowered seeing the increase in caster. Seconfly what bushes did you change at the front? Did you use any alignment type bush or you just have one you want to use?
The disparity could be down many things and can be narrowed down depending on your answers. I suspect it's to do with unequal ride height side to side.
I'm not a fan of the alignment type bushes as the a not accurate and the range us too small to be of value.
I also like to find any issues rather than band aid it however the effective way to correct this is with adjustable front UCAs. The added benefit is you can dial in more camber to get that biiisssssssh to corner like on rails.
SPL, Kinetix or eibach get my vote. Cusco, ichiba, D2, k sports and all the other knock off will fail.