Well, the video card isn't certified for Solidworks but that doesn't mean it won't work
It sounds like the maximum screen resolution of the Surface book might be the identifying factor and that your video card doesn't support 4K output in the OpenGL buffer.
you might try tweaking your display buffering settings in the nVidia Control panel. Try turning off triple-buffering.
Another thing to check is the motherboard GPU. Most notebooks come with the intel HD video chipset integrated into them. It's possible that the display pipeline is getting output from both your onboard GPU and your nVidia graphics card. You might try disabling the onboard video in the BIOS on start-up.
If this is a recent development, I would try rolling your video card driver back to an earlier release. Since GeForce cards aren't certified for Solidworks, it may be that a change in the way displays are switched in the driver could introduce this new behavior as an artifact.
thank you for your answer, John. Unfortunately I can enter the Bios only for the start oportunities and the other standard things but nothing to stop one of the GPU's. The bios allows only a few general settings. There also don't exist any real Nvidia control panel, only a smal version where I can specify which programs should run the external Nvidia GPU. But you're right it seams that both GPU's are trying to offer a Picture on 4K external screen.