I am in this exact same situation right now with my 2019 Lexus RX FSport.
They have replaced all the front sensors, the circuit board (I think that's what he called it) and the problem still exists.
I was just told they think it is a software problem but the software to fix it IS NOT EVEN WRITTEN YET!!! Estimating 9-12 months before they come up with a solution.
Lexus corporate has gotten involved. They even flew someone in that wrote the program to collect data from my vehicle.
Lexus is not volunteering to buy the vehicle back.
Anyone initiate a Lemon Law buy back??