I am intrigued some people believe it could be the dock itself. I have a SB1, SB2, and SB3, Two dock v1, and a dock 2. The issue happens only with the SB3, and with all docks. Swap in SB2 or SB1, they have never had any issues with any docks.
Beyond this, a work colleage has an SB2 and SB3 and Dock v1 and dock 2. He never had any troubles with any of that till this week. Suddenly, no monitprs on the docks, and no usb on the docks. Laptop usb is ok.
The connector could be a possible cause. Maybe the connector just does not connect correctly. The manufacturing issue could be sometimes on the plug side and sometimes on the socket end. That would explain some resolving it with new dock, and some with new (or older) SB.
I agree, I have 2 SL3s, a SP4, and a SB3. Had a dock v1, then switched over to a Dell WD19 USB-C dock, and just recently switched to a dock v2 since I initially suspected a low power issue. All of the PCs aside from the SB3 have worked properly with all 3 of the docks.
With the SB3 all of my devices work properly (Dell UltraWide monitor, USB DAC, USB webcam, USB BD drive) except for my Razer Ornata (keyboard) and Razer Mamba (mouse). The keyboard constantly disconnects and reconnects to the point that it is unusable. The mouse usually works alright, but occasionally stops responding when the keyboard does.
I have adjusted the USB power settings, even plugged the keyboard and mouse directly into the SB3, but nothing seems to work. I reset the SB3 and did a clean Windows 10 installation earlier today - that has not helped either.
I suspect that there is some sort of connectivity issue between the tablet and keyboard base unit, since the Surface Connect port, USB-C port, and USB 3 ports are on the keyboard base unit. I have not tried connecting the tablet to the dock v2 without the keyboard base unit yet, but that would defeat the purpose of this laptop since the GPU would then be disconnected. However, that could be the issue since the SL3's and SP4 do not have their hardware split between 2 detachable pieces.
I just submitted a service request for the SB3 and it will be replaced with a new unit under warranty. I'm hoping that whatever the issue is with this current SB3 does not present itself in the replacement.
EDIT: I've tried connecting the Dock 2 to the surface connect port on the tablet itself, but I'm still having the same issue. I even uninstalled USB devices and did a scan for new hardware. This leads me to believe that there is an issue with the hardware within the tablet portion itself and not in the keyboard dock. I'll be boxing up the SB3 today to return it. Once I receive the replacement I'll provide an update on whether the issue is resolved.
I received my replacement SB3 today. I plugged it into the same Dock 2 my last one had issues with (same accessories mentioned above) and everything works flawlessly now.
This seems to confirm that my last device had a hardware issue - in addition to the fact that 3 other Surface devices had no issue with my dock setup. I encourage anyone with an active warranty who is experiencing the same issue to initiate a warranty replacement before your warranty expires.