Check the TRE's.
Check the Rake of the car (from the two jaking point cut out square sections to the floor. depending on tyre wear it should be 10 to 15 mm ... 10mm for even tryes adjust more for every mm front tyre is below the rear). ADjust rear suspension as necessary.
Check tracking

The front wheels sound like they are tramlining (bumpsteer). which can be caused by having parallel tracking on the front. Also if the tyres are wider than standard the wheels are more prone to tramilining.

are the front dampers fitted on the correct side. Not sure about the ones you have but standard ones have a left and a right with the tabs pointing slightly backwards.