I tested it on all available USB ports on my laptop, but the problem remained as long as I had phantom power engaged. It is an Mobile Intel® HM55 Express Chipset Intel | Data Center Solutions, IoT, and PC Innovation
I also tested it on my desktop machine which has a Gigabyte motherboard. Model:
GA-Z68X-UD3P-B3 (rev. 1.0)
Intel® Z68 Chipset
I had exactly the same issue on both systems.
As I said, my main desktop DAW uses a UR824, which does not have any problem with any of my mics and there is no grounding problem in the system.
Steinberg hasn’t replied to my support email, in which I detailed all of the things I had tested up to that point. Now I have tested even more, and I am 100% certain it is not a fault in my system(s). I can only conclude that the device is faulty (or poorly designed/wasn’t tested on a wide range of devices).