Might be worth downloading an earlier (g2) version of the app to see if it works with your g3. You can google watteam powerbeat app 3.0.9 apk.
The problem i am having is that the older app version won’t detect the powermeter. The figures do appear on my fenix 3 and on the wahoo utility app on my phone, but the powerbeat app won’t detect anything. Anyone had this and found a solution?