Exercise Circle

I have an Apple watch 3. I have noticed that since October 2 the exercise ring does not record all the exercise from a workout. I used to get 30 minutes credit for my dance exercise class, now I get 3-6. I just completed a challenge for October that was for 5 30 minute workouts and I got full credit. What has changed? Before COVID, when I attended a class regularly, there was no problem. Now I get very little credit. Same class except I am doing it virtually.