The U.S. Customs and Border Protection (CBP), at the request of the Federal Communications Commission (FCC), has detained the imports of Bitmain's Antminer S21 and T21 series ASICs at ports across the country for up to two months. Seven U.S. mining companies have not received a clear explanation for the delays or a timeline for resolution. Industry speculation suggests that this may be related to a review of chips from Xiamen Sophgo, which is under investigation for potential violations of U.S. sanctions. While there is no direct evidence linking the import suspension to these investigations, sources indicate that the FCC and CBP may be checking for restricted components in the shipments. This incident highlights the tensions at the intersection of U.S. trade policy and technology regulations.