The issue is when the US Government tries to tell private US Companies who and how they should do business with certain foreign companies, and forgets to provide any actual evidence for their assertions.
This all could be avoided by simply publishing what Huawei is meant to have done. Otherwise it just strikes of a trade-war/protectionism but using "cyber security" as a justification.
Article VI Debts, Supremacy, Oaths, Religious Tests
Signed in convention September 17, 1787. Ratified June 21, 1788
...
This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding.
This is not at all a treaty. Actual treaties require a 2/3rds approval of the Senate, which has not happened.
It is, at best, on the level of 'executive order', which can (and, IMHO, should) be challenged in court per 'checks and balances'.
I think it's more likely this derives simply from some Federal level law which is why it gets its power over states and individuals.
The carnival atmosphere in Washington is bad for everyone. The Tweeter-in-chief undermines his own authority by governing in the public square. It makes any counter-party position much stronger, as they can easily manipulate the emotions of the president, and the negotiators on the ground have very little leverage within the US camp. A random ad on TV may change strategy!