VIMEO embeds in Mobile App

VIMEO embedded videos aren't playing in Heartbeat Android app. Heartbeat is the only platform I've had this issue with - the likes of Mighty Networks, Circle, etc - don't have an issue with Vimeo vids refusing to play in Android apps. It's NOT an issue of restricting Vimeo domains (multiple users have lifted all domain restrictions for Vimeo videos, and they still don't play in Heartbeat Android apps).