So without reading through this whole thread... I would agree that this is something new and for me only has been happening for the last couple of months. This is occurring on my Surface Book 2 when connected to a Surface Docking station version 1 and is only for usb devices connected through the docking station.
However I did notice it only occurs when my system in under heavy use (power consumption). When the problem happens I can hear my internal fan blowing hard and I usually have Photoshop or my security cameras open, which are 4K. The problem will continue until I close one of the heavily consuming apps (i.e. security camera). As soon as I close one of these apps, the problem immediately stops.
Now if I remember correctly, I saw another thread that say the original docking station (version 1, with the mini display ports) is under-powered for the Surface.... but then I can also fall back and say I didn't experience this a few months ago.
I would see if when this occurs is yours system under heavy use.
David