Octagons begone! I want circles!

Problem. Some of my circles are appearing as octagons. They look fine in preview mode, but once I try to export them they form sides instead of being round.

See, I have these orange circles, they’re all appearing fine. The black circles, which are just slightly larger, are the ones causing the problems. They’re all being duplicated about 100 times.

Yes, my quality is set to highest.