multiple custom renderer weirdness

I have a forms page that is a checklist, containing about 20 XLabs SegmentedControlViews. These get custom rendered into UISegmentedControls in iOS. When I place 20+ of them in a TableView I am getting cross-coupled changed events where if one changes the value of one control it changes another ten to fifteen items up, varying based on orientation. The renderer is checking for null before calling in OnElementChanged before calling SetNativeControl. Wondering if there are other event handlers I should add to the custom renderer?

Thanks,
Bob