When you receive your FamilyBoard, Battery Optimization will as a standard be turned off for the app.
This is because FamilyBoard and the syncing with external calendars works best it battery optimization is turned off. But is needs to be selected for each app individually.
For new apps you install on the FamilyBoard, Battery Optimization will be by default be on. So in any situation you have had to uninstall and reinstall the FamilyBoard app, it will be battery optimized again. In this video we show you how to turn off battery optimization for FamilyBoard so that it runs smoothly: