I have a Akitio Thunder3 Box, a Dell DA-2 PSU, and a GTX960 connected to my Lenovo P50 laptop via TB3. I hooked up my 4k TV to the 960 and it will not output 4k even though it would when it was in my desktop hooked up to the same screen. Windows thinks it's outputting video and audio to the tv but it's not getting there.
I also can't get applications to use the card instead of the iGPU without having an external screen attached and running apps on that screen.
I think I'm doing something wrong but I'm not sure what.