I have the same issue. I have a Surface Book 2 (Model 1793 i7). I reported the issue and was sent a replacement dock. Didn't fix it.
It is at the point where to get the dock to connect faster I start the Dock Update tool and run that when the dock disconnects. That seems to have the system refresh faster and allow for the devices to reconnect. One thing is for sure I am not getting a Surface for my next laptop. This has (and continues to be) such a huge pain.
The only thing that the dock is used for is to connect monitors and internet. Power only provided to the laptop.
I did not get a new dock, I got a new power supply. I am told that it is the power supply that is causing this problem. There is a "bug" in the old ones.
Same problems as most of the folks in the thread. Intermittent connection and disconnection on the dock. I would love to try with a new power supply. Is there a particular power supply you bought? Thank you