I am getting a strange result when exporting an SVG icon from Sketch.
I am trying to export this mail icon that is made up of two masked triangles and an outer rectangle (all using an outside border):
The resulting SVG is misaligned, with some of the icon missing:
I am fairly new to Sketch and graphic design in general.
I suspect this has something to do with my groups, masks, or incorrectly 'flattening' the icon.
Any help is much appreciated.
Edit 1 - Result when I Union all the layers: