react-native-canvas loses canvas ref when navigating with react-navigation

[MooBooty]

So testing an app with 2 screens combining react-navigation and react-native-canvas (basically a config screen and a canvas screen). Not sure how to either gracefully destroy the canvas before leaving screen or maintain canvas reference while navigating. It seems the ref prop of is called when navigating to or away from the screen. The effect is that the app crashes with error "TypeError: Cannot set property "height" of null.

Sorry if this is in the literature and I just didn't see it.