Surface Dock keeps disconnecting/reconnecting USB devices with Surface Book 2

Late reply, but still a relevant issue. I tried the powered USB hub and did not have any different results. I was thinking the same thing as you.

So my wife's Surface Book 3 is having a similar problem using multiple monitors on a Surface Dock 2. When plugging into the dock, there is a constant plugging and unplugging sound, and the Microsoft wireless mouse doesn't function. I have to unplug and re-plug the dock connector and cross my fingers it works. To stop the beeping of the plugging and unplugging sound, the Device Manager needs to be open (really weird). If the Device Manager is open when docking, the plugging and unplugging sound does not persist.

I've already contacted MS once and they had me update to the latest version of Windows (it was on 1909). That did not help, so I'll be contacting them again.

One week with the replacement SB3 and so far there have been no issues whatsoever. I use it extensively each day, while connected to my Dock v2.

One thing I noticed is that the new SB3 does not show the performance slider when clicking on the battery tray icon - my old SB3 did. The new SB3 also has a “Balanced” and “High Performance” power plan, whereas the old SB3 only showed “Balanced”. I’m convinced Microsoft made some sort of firmware or hardware change that is reflected in the replacement unit.

I have a Surface Book 2 and was experiencing this annoying issue. It appeared that the Surface dock was power-cycling and all my external USB devices would disconnect and then reconnect. This happened frequently, many times a day. Particularly, it occurred during video calls/Teams meetings. 

I purchased a 3rd party AUKEY USB dock and have retired my Surface dock altogether. Happy to report I'm not experiencing this issue anymore. I'm using the power supply that came with my Surface Book (I used to power it through the dock) and connecting to my monitor through HDMI connected to the new 3rd party USB dock. All my other devices (webcam, keyboard, mouse etc. are also connected through the 3rd party dock.)

It seems the issue was related to the Surface Dock itself, not my machine. Hope this helps someone else!

Disabling "Allow the computer to turn off this device to save power" fixed my issue with Razer keyboard and mouse disconnecting/reconnecting every few minutes. (And it's a good thing, too...because it was about to drive me up the WALL!)