DX12 Display "glitches"

Hi, sorry if this is not the Right Place to post this.

So I just got the new windows 10 Release and with that the ability to activate DXR for Unreal.
But at the moment I try to enable DX12 for the editor this glitch happens.

Every klickable surface will be “zoomed” in to the size of the window.
the engine starts normally and works fine. but the moment I try to click open a Dropdown menue the whole menue is stretced across the whole screen.
when navigating in the Viewport the problem disappears.

Installed Hardware (maybe that helps)
Processor: I7 4790K
GPU: Asus Gtx1070 + Gigabyte Gtx1070 ( without enabling alternate Frame Render)
Ram : 16 GB DDR3

The Engine runs on a SSD

Forgot to attach the screenshots. Can’t edit my own post apparently.