2021 Lexus LS Engine Problems

My vehicle has the V6 twin turbo engine that’s been recalled on other years and models and was diagnosed with an internal engine failure. The mechanic at the dealership couldn’t figure out the problem so an expert TAS Lexus specialist was called in and couldn’t figure out the problem either. They’ve had the car for 3 months and since they don’t know how to fix it they are telling me to just replace the engine with a used engine at a cost of $25,000. The vehicle is just out of warranty and Toyota/Lexus is refusing to cover any of the costs. The vehicle was serviced regularly so this shouldn’t have happened. This is a common problem with this model of engine. I believe it’s a design flaw as this model engine is assembled at different plants/locations and over long periods of time that would indicate a design flaw and not due to Toyota’s official stance of debris left in engine block during assembly. Toyota should recall and replace all these engines at no charge to the owner of the vehicle.