Because of components from China: Around 13,000 new Audi and Porsche cars are stuck in US ports. The reason: The cars contain parts from western China - which also includes the Xinjiang region.
Volkswagen has long been criticized for its activities in western China. The component in question is not allowed to be used in the USA because of a local law against forced labor. However, Volkswagen itself had no knowledge of its origin. Volkswagen only found out about this through a tip from the supplier and then informed the US authorities itself.