Magisk cts check is broken, and may forever be like that. Google seems to have started using hardware to check for bootloader unlock.
As stated in the op, the sm-n9750 is the device in question here. Not any USA snapdragon variant.
sm-n9750 is used in Asian countries and some south American.
It's completely unlockable and rootable, and is more compatible with the American carriers than the exynos devices. This is why I buy the Chinese models, and use them on T-Mobile USA