Polar device linking

I require urgent assistance with syncing my workouts and steps with the Discovery app. first time I linked it it didnt sync even after waiting 24 hours. Then delinked and relinked. then it synced but only took my steps and not my 30 min workout with 80% average heart rate. Then the next day it didnt sync after midnight. Then i delinked it again and relinked it and now doesnt sync. Why is there not the same support with the Polar A370 device as there is with the fitbit charge2. The discovery app continuously syncs with the fitbit app and points are shown immediately. With the Polar it doesnt at all. I was told that that Discovery app works the same with the 2 different devices. I have spent lots of money for this device and now discovery app doesnt want to work correctly. I want to earn my workout points when I train. Its the main reason I purchased this.