Cant choose graphic card for unreal editor

I have pc with 3 graphic cards: 1x gtx1060 for system and 2 x gtx 1080ti.
I want unreal engine to use one of the 1080 but i cant make it work. In nvidia panel i chose proper graphic card (look at attachment) but when i run editor only gtx1060 works. In other apps like substance painter everything is fine. thanks for help!

Hi, did you ever find a solution to this issue please? Thanks!