>On the face of it, it does seem pretty silly that a company that had sanctions against it (ignoring for the moment how appropriate one may think those sanctions are) can avoid them by spinning off a subsidiary that is purchased by a group of investors led by the Chinese government, and claiming it is somehow different than Huawei.
The sanctions are bureaucratic artifact and this work around is also a bureaucratic artifact. I'd guess that Honor is being ignored because the original sanctions were illogical and were doing harm to both business in the US and the US's image overseas. Having imposed them, though, the government can't just go "Oops, my bad!" and remove them so there has to be some kind of alternative.
I'd guess the sanctions imposed unilaterally on Iran over the nuclear deal are in the same category. We can't just un-impose them, that would look like losing, so we're stuck with finding a way to justify un-imposing them as some kind of win for the US. (Like Huawei, the situation is complicated by there being plenty of 'hawks' who are pushing for even more sanctions.....government is never clear cut.)