Wrong XCode specified in 4.17

When attempting to use 4.17 editor, the error message comes up stating that my XCode can’t be used for metal shaders and that I should install XCode 8.3. I am on XCode 9.0. The Mac is on current High Sierra (10.13) and has the most recent XCode. I don’t think I can downgrade XCode for Unreal without downgrading to Sierra. Is this a bug and if so, is there any workaround?