Have you tried combing only one of the round shapes instead of both together?  If not, try combining with one shape, and then import the object again and combine the other round shape.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi