Not sure if its a bug, or there is a work around.
So below I have the same ellipses, the top as an element, the bottom contained in a symbol.

The display is different on output.
The css property changes for the one inside the symbol to "circle farthest-corner" instead of remaining as "ellipse farthest-corner".
Let me know if anyone can help me sort this out. Cheers.
Output:
