Hi, rodipoet.
What is your computer? Laptop x desktop? Do you know the chipset model? Have you tried on others desktop and laptops?
Steinberg Support answered me that with the only one returned unit with this noise issue, they did tests on multiple machines and don’t have the problem… They said that in similar cases they had seen - including other brands - the cause is usually on a specific system and caused by computer’s USB power system.
I also think that must be a design problem, maybe related to insufficient power only when the Phantom Power is activated.