Apple watch series 6 vs wahoo tickr calories disparity

hello gang notice a big disparity in calories when i compare my apple watch workouts to my wahoo tickr strap, the heart rate accuracy is awesome but the disparity in calorie counting in the app is off after a 30/40 min workout by around 140-150 calories i’m not looking for incredible accuracy but i also tested the with my polar h strap and that app closely mirrors wahoo ; any suggestions for me?