Watch not tracking activity from Polar Beat / Polar Flow

I just got the new Apple Watch and wanted it specifically to track sports, activity and burnt calories. Got a heart rate sensor from Polar too to get more specific data. Polar sensor, Watch and my iPhone connect perfectly but for some reason, even though the Health app has all the necessary sources and permissions ticked my watch doesn't count all my burnt calories from Polar Beat app or Polar Flow app. The activity app also says that the heart rate chart isn't available and asks to make sure that the app used to track the training has the permission to track heart rate in either Watch's or iPhones setting. I've double checked this so many times and even though everything should be in order, the activity app doesn't track all the info on Polar's app. This leaves me short of my calorie target and training target almost daily, even though in Polar app all the targets are met.

Any advice on how to get this to work so my workouts "don't go to waste" and I get data that actually is correct? Kinda puts me off from wearing the watch since it doesn't work as it should and I can't get all the fun out of it...