Darane

So you have 2 screens and apparently wow uses the other one. Try to reverse the screen order in screen settings.

I got new LG 3440x1440 (LG 34UC88-B) screen and wow 1.12 works fine in native resolution. I had to select compatiblity mode for win7 and run as administrator to have the wide resolutions available. I play on Dell 7559 laptop with Windows 10 x64, build 1607, max patched.