Japanese CPU designer Arm has a facility in Austin, Texas, USA, that validates Arm-compatible and licensed chip designs for customers around the world, including those in China, and thus is restricted by the White House's latest crackdown.
Moral of this story. Don't do business with the US, they will turn on you whenever it's financially beneficial for them and unilaterally break deals, without any means for recourse.
An unreliable partner. Like any other bully, best to let them play in the sandbox by themselves.