This might be a known bug or related to the bug (https://github.com/gnif/LookingGlass/issues/27) or similar but I am not sure if this exact behaviour has been reported yet.
Waiting for a Dummy HDMI Plug I now hooked up a 1080p monitor.
As soon as I boot the VM with it I get a completely unusable mouse (the mouse just feaks out all over the place).
I believe I removed the Tablet that people refered to with similar issues but I can’t be sure. The virtual PS/2 mouse in virt-manager can not be removed apparently.
What am I doing wrong?