Apple watch workout tracking

My apple watch doesn’t track my workouts correctly. For example, I did a hiit workout for 40 min, my heart rate was 180 and I burned 235 calories.

I did that workout before and burned 340 calories.

So my apple watch isn’t working correctly right now. I tried it with other workouts and I’ve burned just a little in al of these workouts.

I already tried shutting the apple watch off and to calibrate it, but that didn’t work.