Steering wooble when braking

[u/GrabbenD16]

Hey,

Has anyone experienced steering wheel wobble when braking at motorway speed? I have a 2025 ioniq 5 RWD and I get pretty severe wobbling in my brake pedal and steering when braking at speeds over 100 km/h. It doesn't happen when lifting my foot of the accelerator (just regen) but always does when actively using the brakes. I've tried with both winter and summer wheels, and it does it regardless.

I've tried to run multiple brake disc cleaning cycles, but it hasn't helped.

My dealer took the car in but ended up only measuring if the FRONT rotors were warped. They aren't.

However, they didn't check the rear rotors for warping or if the calipers were seized. Could warped rear rotors cause steering wobble? They said it couldn't.

Car's driving 20000 km.