Surface Book 2: External Monitor Flickering

Thank you so much, I think this was the solution for me. I went completely berserk: nothing worked!! This now seems to do the trick!

I had a similar problem.  At first things were good, I'd get a flicker once every few hours.. it was survivable.

Today it was happening once every few minutes.

I started by updating the drivers, then reducing the refresh rate, then swapped from a USB-C to USB-C connection, to a USB-C to HDMI converter, in to an HDMI port.. and it continued.

Then.. I solved it.

I disconnected the screen, and re-connected it.  Hasn't flickered since.

Check the connection between monitor and base.

Good luck!

I adjusted my displays refresh rate and the problem is gone

This same flickering problem started almost immediately with my Surface Book 2 - 13.5 (purchased mid-2017) connected through the Surface Dock via Cable Matters active HDMI to Mini DisplayPort adapter coupled with Cable Matters HDMI cable to an HP Pavilion Q32 monitor. (I've tried multiple cables, adapters, and approved monitors).  The flickering occurs with the laptop screen up or down and the flickering occurs on both the laptop monitor and external monitor.  Typically while the laptop monitor is flickering the external monitor just 'cuts-out' completely. 

Initially I thought it was only a Surface Dock problem so I exchanged the Dock twice.  Took my Surface Book 2 and Dock into the Microsoft Store to have it diagnosed (that's when they gave me one of the two new Docks.)  Also tried USB-C connected directly to the monitor (problem got worse, flickering became more pronounced and rapid on both laptop and monitor), I've used many types of adapter connectors, cables, downloaded driver updates, Windows Updates, and confirmed monitors were 'approved'.  I've tried dozens of suggestions from the legit blogs.  Still the flicker persists when connected to an external monitor.  My laptop monitor only stops flickering when disconnected from an external monitor. 

It wasn't until I started working with a friend who's a Microsoft engineer that we started (getting close to) isolating the problem.  He doesn't have the same problem with his Surface Book (1).  He believes that since there are two separate graphics cards and drivers in this system (one for the tablet and one for the base) he thinks there's got to be a conflict with some of the '2' units when connected to external monitors.  He's unsure of what's different 'hardware-wise' between the '1' and '2'.  He recommended I schedule another visit to my Microsoft Store.  I'm going tomorrow morning.   

While typing this response, I've had my Surface Book 2 connected to the Surface Dock (external monitor disconnected) and ran the Base Mark Web 3.0 benchmark test, no problem with the laptop monitor flickering.  So I don't think the problem is with the Dock as much as it's with the data exchance between the monitor and the laptop's dual graphics cards.

I have the same issue -- SurfaceBook connected to surface doc, connected to two external monitors -- the monitors flicker / drop connection for about 1-2 seconds every 2-4 minutes  throughout the day.

Craig