High CPU Load and no Taskbar with W10.1703 when Taskbar is automatically turned off

[rbm]

Hi,

thank you very much for asking those questions. I was sure my post was missing some vital information, but I was not sure what :-)

I´m using a Surface Pro 3 with the Kensington SD-3500v, one Monitor is on the DVI port, the other on the HDMI port. The Surface screen is always on, so it´s basically a triple screen setup.
The Desktop is expanded over all 3 Screens. The external Screens stand side-by side, the Surface is below them and in Windows I also have that arrangement (see my screenshot, 2+3 external 1 = Surface).
The Taskbar is configured to slide out in Desktop mode and it´s configured to only show up on the Primary Screen which is the one on the top left.

I did not have issues with the Anniversary Update (apart from the mouse lag issue in the very beginning which Displaylink fixed with its driver updates over time ).
Right after the Creators update I was not able to get into my Taskbar once it slided out. CPU usage goes up (see screenshot) and I can´t get the Taskbar back. I had to unplug the USB dock and then in the Windows settings I permantently enabled the Taskbar to fix the issue.
While the taskbar is hidden, there are artifacts of the task bars outer border shown and they flicker like there´s an attempt to show the Taskbar and hide it again. Unfortunately it´s not possible to Screenshot this (I tried it several times, but a Screenshot always shows a clear picture).

All this is not happening when I make the Surface the primary screen (while the 2 externals are still connected) and only show the Taskbar on that one. Then it slides in and out as it should and I don´t see the CPU utilization you can see in the Screenshot. As soon as I make one of the external Displays the primary, the problem comes back.

I hope this helps to reproduce the issue I have. If you need any further information, don´t hesitate to tell me. I´ll try to get whatever you need.

Kind regards :-)