Inconsistent ShapeDiver Results

Is there a reason why geometry will show up sometimes and not others? Are there best practices to avoid this?

I currently have an application I am building with the API and will run it with the same data and sometimes it just does not want to work. (Not to mention that sometimes the exact same data goes over my time limit and sometimes it doesn’t.) I’m getting widely varied results.

Sometimes things will compute, but sometimes they don’t.
Sometimes things will preview, but sometimes they don’t.

Could you share a link so we can have a closer look at the model?