iPhone Forecast doesn't clear past events (iPad does)

I have OmniFocus Pro 3.1.5 on my iPhone and iPad. I have them both set to show calendar events as part of the Forecast perspective. On iPad, past events get removed from the perspective, which is what I want. On iPhone, past events get grayed out but don’t get removed. Am I missing a setting? I don’t want past events showing up in Forecast.