Does this ever get called?
public static void init() {
CapabilityManager.INSTANCE.register(IPlayerCapability.class, PlayerCapability.PlayerStorage.playerStorage, PlayerCapability.class);
}
I didn't see anything like this in your code.
private static class Factory implements Callable<IExampleCapability> {
@Override
public IExampleCapability call() throws Exception {
return new Implementation();
}
}