I've submitted a save game already on this one.
Playing in an immense universe, I have one of the corners, and no close neighbors. Even with extended life support researched, I was unable to get a freighter to any other race. I upgraded the basic freighter with a better engine and 2 extended support modules. That increased the range a small amount, but not enough. I upgraded again, and stuck on 5 or 6 modules. Now my range shows as 10.7, up from 4.something, but the freighter range is now a rectangular area that is generally the same size as my prior range bubble. I live in the top left corner of the map, and the outside corner of the range box does show some jaggedness at that extreme range, but it is otherwise a perfect rectangle. Not just a graphical bug, I cannot pass the line.