OMG such a dumb problem. I had the mirror objects as one smoothing group before export for unreal. When the mirror polygon is its own smoothing group the world normal is flat and the reflection is correct.
Don't use a normal map on the glass parts? Its unnecessary anyways. Its a completely flat surface. A roughness map is more useful. It looks like you have 2 different issues occuring with those normal maps. Image2: Wrong tangent space Image3: low precision normal map.