#127 "ScrollView in modal prevents modal from dismissing sometimes" - https://github.com/react-navigation/stack/issues/127
This issue has a good discussion and a comment:
brentvatne: it's not really possible for react-navigation to guess when you may or may not want to close the modal depending on other gestures you have inside of a scene, you need to define that behavior for yourself. you can access the gesture context like this: https://github.com/react-navigation/react-navigation-stack/blob/5f157cbc16f2dd15363304ab3c78663b0ed36de0/example/src/GestureInteraction.js#L55-L56 then you can use react-native-gesture-handler tools to make this behave how you like.